diff --git a/apps/mobile/src/features/cloud/linkEnvironment.test.ts b/apps/mobile/src/features/cloud/linkEnvironment.test.ts
index a236663c9ea8..1e78f250ef4e 100644
--- a/apps/mobile/src/features/cloud/linkEnvironment.test.ts
+++ b/apps/mobile/src/features/cloud/linkEnvironment.test.ts
@@ -293,7 +293,6 @@ describe("mobile cloud link environment client", () => {
       const bodies: Array<unknown> = [];
       const fetchMock = vi.fn((url: string | URL, init?: RequestInit) => {
         if (init?.body) {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           bodies.push(JSON.parse(requestBodyText(init.body)));
         }
         if (String(url).endsWith("/v1/client/environment-link-challenges")) {
@@ -348,7 +347,6 @@ describe("mobile cloud link environment client", () => {
       const bodies: Array<Record<string, unknown>> = [];
       const fetchMock = vi.fn((url: string | URL, init?: RequestInit) => {
         if (init?.body) {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           bodies.push(JSON.parse(requestBodyText(init.body)) as Record<string, unknown>);
         }
         if (String(url).endsWith("/v1/client/environment-link-challenges")) {
diff --git a/apps/server/src/cli/config.test.ts b/apps/server/src/cli/config.test.ts
index 17072a5e1c35..04f6c3ca7a8c 100644
--- a/apps/server/src/cli/config.test.ts
+++ b/apps/server/src/cli/config.test.ts
@@ -650,7 +650,6 @@ it.layer(NodeServices.layer)("cli config resolution", (it) => {
       yield* fs.makeDirectory(path.dirname(derivedPaths.settingsPath), { recursive: true });
       yield* fs.writeFileString(
         derivedPaths.settingsPath,
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         `${JSON.stringify({
           observability: {
             otlpTracesUrl: "http://localhost:4318/v1/traces",
@@ -722,7 +721,6 @@ it.layer(NodeServices.layer)("cli config resolution", (it) => {
       yield* fs.makeDirectory(path.dirname(derivedPaths.settingsPath), { recursive: true });
       yield* fs.writeFileString(
         derivedPaths.settingsPath,
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         `${JSON.stringify({
           observability: {
             otlpTracesUrl: "http://localhost:4318/v1/traces",
@@ -774,7 +772,6 @@ it.layer(NodeServices.layer)("cli config resolution", (it) => {
       yield* fs.makeDirectory(path.dirname(derivedPaths.settingsPath), { recursive: true });
       yield* fs.writeFileString(
         derivedPaths.settingsPath,
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         `${JSON.stringify({
           observability: {
             otlpTracesUrl: "http://localhost:4318/v1/traces",
@@ -1073,7 +1070,6 @@ it.layer(NodeServices.layer)("cli config resolution", (it) => {
         yield* fs.makeDirectory(path.dirname(derivedPaths.settingsPath), { recursive: true });
         yield* fs.writeFileString(
           derivedPaths.settingsPath,
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           `${JSON.stringify({ observability: { otlpLogsUrl: "http://settings:4318/v1/logs" } })}\n`,
         );
 
@@ -1145,7 +1141,6 @@ it.layer(NodeServices.layer)("cli config resolution", (it) => {
         yield* fs.makeDirectory(path.dirname(derivedPaths.settingsPath), { recursive: true });
         yield* fs.writeFileString(
           derivedPaths.settingsPath,
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           `${JSON.stringify({ observability: { otlpLogsUrl: "http://settings:4318/v1/logs" } })}\n`,
         );
 
diff --git a/apps/server/src/cli/pair.test.ts b/apps/server/src/cli/pair.test.ts
index 39fe8652ce61..77cd8f1f0bc9 100644
--- a/apps/server/src/cli/pair.test.ts
+++ b/apps/server/src/cli/pair.test.ts
@@ -173,7 +173,6 @@ describe("t3 pair", () => {
         const listed = yield* captureStdout(
           runCli(["auth", "pairing", "list", "--base-dir", baseDir, "--json"]),
         );
-        // @effect-diagnostics-next-line preferSchemaOverJson:off - CLI JSON output is decoded as a presentation DTO.
         const credentials = JSON.parse(listed) as ReadonlyArray<{ readonly label?: string }>;
         assert.equal(credentials.length, 1);
         assert.equal(credentials[0]?.label, "t3 pair");
diff --git a/apps/server/src/cloud/bootService.test.ts b/apps/server/src/cloud/bootService.test.ts
index 4d8bae4377c4..85de4a7bd437 100644
--- a/apps/server/src/cloud/bootService.test.ts
+++ b/apps/server/src/cloud/bootService.test.ts
@@ -359,7 +359,6 @@ it.layer(NodeServices.layer)("boot service install", (it) => {
         current: true,
         installedVersion: "1.2.3",
       });
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed launcher-owned test document.
       const pendingState = JSON.stringify({
         protocol: SERVICE_LAUNCHER_PROTOCOL,
         activeVersion: "1.2.3",
@@ -546,7 +545,6 @@ it.layer(NodeServices.layer)("boot service install", (it) => {
     Effect.gen(function* () {
       const { service, fs, statePath } = yield* makeHarness();
       yield* service.install();
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed launcher-owned test document.
       const pendingState = JSON.stringify({
         protocol: SERVICE_LAUNCHER_PROTOCOL,
         activeVersion: "1.2.3",
@@ -647,7 +645,6 @@ it.layer(NodeServices.layer)("boot service install", (it) => {
     Effect.gen(function* () {
       const { service, fs, statePath, commands } = yield* makeHarness();
       yield* service.install();
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed launcher-owned test document.
       const pendingState = JSON.stringify({
         protocol: SERVICE_LAUNCHER_PROTOCOL - 1,
         activeVersion: "1.2.3",
@@ -808,7 +805,6 @@ it.layer(NodeServices.layer)("boot service install", (it) => {
       const { service, fs, statePath, commands } = yield* makeHarness("darwin");
       yield* service.install();
       const plistPath = (yield* service.status).unitPath;
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed launcher-owned test document.
       const pendingState = JSON.stringify({
         protocol: SERVICE_LAUNCHER_PROTOCOL - 1,
         activeVersion: "1.2.3",
diff --git a/apps/server/src/cloud/selfUpdate.test.ts b/apps/server/src/cloud/selfUpdate.test.ts
index 2ee84535470c..111b62c8a481 100644
--- a/apps/server/src/cloud/selfUpdate.test.ts
+++ b/apps/server/src/cloud/selfUpdate.test.ts
@@ -84,7 +84,6 @@ const makeHarness = Effect.fn("test.make_self_update_harness")(function* (
                 launcherProtocol: SERVICE_LAUNCHER_PROTOCOL,
               };
         return {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off - fake child-process stdout.
           stdout: JSON.stringify(result),
           stderr: "",
           code: ChildProcessSpawner.ExitCode(0),
diff --git a/apps/server/src/device/SshDeviceHost.test.ts b/apps/server/src/device/SshDeviceHost.test.ts
index f0d0a7ece0ae..871f66bae0d6 100644
--- a/apps/server/src/device/SshDeviceHost.test.ts
+++ b/apps/server/src/device/SshDeviceHost.test.ts
@@ -1,4 +1,3 @@
-// @effect-diagnostics preferSchemaOverJson:off - the external process fixture emits raw JSON over SSH stdout.
 import { expect, it } from "@effect/vitest";
 import * as NodeServices from "@effect/platform-node/NodeServices";
 import * as Net from "@t3tools/shared/Net";
diff --git a/apps/server/src/device/sshDeviceScript.test.ts b/apps/server/src/device/sshDeviceScript.test.ts
index 8d9bc77d891c..f1f56c715e60 100644
--- a/apps/server/src/device/sshDeviceScript.test.ts
+++ b/apps/server/src/device/sshDeviceScript.test.ts
@@ -1,4 +1,4 @@
-// @effect-diagnostics nodeBuiltinImport:off globalFetchInEffect:off preferSchemaOverJson:off - verifies generated remote scripts using real shell and Node processes.
+// @effect-diagnostics nodeBuiltinImport:off globalFetchInEffect:off - verifies generated remote scripts using real shell and Node processes.
 import * as Effect from "effect/Effect";
 import { HostProcessPlatform } from "@t3tools/shared/hostProcess";
 import { describe, expect, it } from "@effect/vitest";
diff --git a/apps/server/src/git/GitManager.test.ts b/apps/server/src/git/GitManager.test.ts
index 8f743c65fa31..95b99fb2c433 100644
--- a/apps/server/src/git/GitManager.test.ts
+++ b/apps/server/src/git/GitManager.test.ts
@@ -790,7 +790,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 13,
@@ -835,7 +834,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 14,
@@ -875,7 +873,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 0,
@@ -928,7 +925,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 16,
@@ -1042,7 +1038,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       };
       const { manager, ghCalls } = yield* makeManager({
         ghScenario: {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           prListSequence: [JSON.stringify([existingPr]), JSON.stringify([existingPr])],
         },
       });
@@ -1095,7 +1090,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 217,
@@ -1138,7 +1132,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
           prListSequence: [
             "[]",
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 114,
@@ -1244,7 +1237,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 216,
@@ -1296,7 +1288,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 221,
@@ -1347,7 +1338,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 217,
@@ -1410,7 +1400,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListByHeadSelector: {
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             "feature/deleted-fork-branch": JSON.stringify([
               {
                 number: 218,
@@ -1492,7 +1481,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 219,
@@ -1545,7 +1533,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 220,
@@ -1719,7 +1706,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager, ghCalls } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 215,
@@ -1768,7 +1754,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager, ghCalls } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 214,
@@ -1991,7 +1976,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager } = yield* makeManager({
           ghScenario: {
             prListSequence: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 1661,
@@ -2045,7 +2029,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListSequence: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 488,
@@ -2111,7 +2094,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListByHeadSelector: {
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               main: JSON.stringify([
                 {
                   number: 777,
@@ -2187,7 +2169,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListByHeadSelector: {
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "effect-atom": JSON.stringify([
                 {
                   number: 1618,
@@ -2199,7 +2180,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
                   updatedAt: "2026-03-01T10:00:00Z",
                 },
               ]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "upstream/effect-atom": JSON.stringify([
                 {
                   number: 1518,
@@ -2250,7 +2230,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 22,
@@ -2289,7 +2268,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 23,
@@ -2325,7 +2303,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager, ghCalls } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 54,
@@ -2365,7 +2342,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListByHeadSelector: {
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             "feature/pushed-plain": JSON.stringify([
               {
                 number: 88,
@@ -2420,7 +2396,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
           ghScenario: {
             prListByHeadSelector: {
               // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "feature/fork-plain": JSON.stringify([
                 {
                   number: 89,
@@ -2476,7 +2451,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListByHeadSelector: {
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             "feature/fork-settle": JSON.stringify([
               {
                 number: 91,
@@ -2524,7 +2498,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListByHeadSelector: {
             // Fake gh returns raw JSON stdout, matching the CLI boundary under test.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             "feature/sticky-plain": JSON.stringify([
               {
                 number: 90,
@@ -2564,7 +2537,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 45,
@@ -2698,7 +2670,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       };
       const { manager } = yield* makeManager({
         ghScenario: {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           prListSequence: [JSON.stringify([existingPr])],
           failWith: new GitHubCli.GitHubCliUnavailableError({
             command: "gh",
@@ -2742,7 +2713,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         };
         const { manager } = yield* makeManager({
           ghScenario: {
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             prListSequence: [JSON.stringify([existingPr])],
             failWith: new GitHubCli.GitHubCliUnavailableError({
               command: "gh",
@@ -2791,7 +2761,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       };
       const { manager } = yield* makeManager({
         ghScenario: {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           prListSequence: [JSON.stringify([existingPr])],
           failWith: new GitHubCli.GitHubCliUnavailableError({
             command: "gh",
@@ -2831,7 +2800,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       };
       const { manager } = yield* makeManager({
         ghScenario: {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           prListSequence: [JSON.stringify([existingPr])],
           failWith: new GitHubCli.GitHubCliUnavailableError({
             command: "gh",
@@ -2874,7 +2842,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       };
       const { manager } = yield* makeManager({
         ghScenario: {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           prListSequence: [JSON.stringify([existingPr])],
           failWith: new GitHubCli.GitHubCliUnavailableError({
             command: "gh",
@@ -3469,7 +3436,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
           ghScenario: {
             prListSequence: [
               "[]",
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 77,
@@ -3605,7 +3571,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             "[]",
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 303,
@@ -3652,7 +3617,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             "[]",
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 404,
@@ -3704,7 +3668,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
           defaultBranch: "",
           prListSequence: [
             "[]",
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 505,
@@ -3744,7 +3707,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager, ghCalls } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 42,
@@ -3798,7 +3760,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListSequence: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 142,
@@ -3875,7 +3836,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListByHeadSelector: {
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "effect-atom": JSON.stringify([
                 {
                   number: 1618,
@@ -3885,7 +3845,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
                   headRefName: "effect-atom",
                 },
               ]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "upstream/effect-atom": JSON.stringify([
                 {
                   number: 1518,
@@ -3935,9 +3894,7 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListByHeadSelector: {
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "t3code/pr-142/statemachine": JSON.stringify([]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               statemachine: JSON.stringify([
                 {
                   number: 41,
@@ -4003,7 +3960,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListByHeadSelector: {
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               statemachine: JSON.stringify([
                 {
                   number: 142,
@@ -4021,7 +3977,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
                   },
                 },
               ]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               "t3code/pr-142/statemachine": JSON.stringify([]),
             },
           },
@@ -4264,7 +4219,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequence: [
             "[]",
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 88,
@@ -4385,7 +4339,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         const { manager, ghCalls } = yield* makeManager({
           ghScenario: {
             prListSequence: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 1661,
@@ -4403,7 +4356,6 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
                   },
                 },
               ]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 188,
@@ -4466,9 +4418,7 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
         ghScenario: {
           prListSequenceByHeadSelector: {
             statemachine: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([]),
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 {
                   number: 188,
@@ -6084,9 +6034,7 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
       const { manager } = yield* makeManager({
         ghScenario: {
           prListSequence: [
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([]),
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 number: 201,
diff --git a/apps/server/src/keybindings.test.ts b/apps/server/src/keybindings.test.ts
index df5175ef65a3..38b6b3a9c205 100644
--- a/apps/server/src/keybindings.test.ts
+++ b/apps/server/src/keybindings.test.ts
@@ -219,7 +219,6 @@ it.layer(NodeServices.layer)("keybindings", (it) => {
       const { keybindingsConfigPath } = yield* ServerConfig.ServerConfig;
       yield* fs.writeFileString(
         keybindingsConfigPath,
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         JSON.stringify([
           { key: "mod+j", command: "terminal.toggle" },
           { key: "mod+shift+d+o", command: "terminal.new" },
diff --git a/apps/server/src/mcp/AcpMcpOverAcpBridge.test.ts b/apps/server/src/mcp/AcpMcpOverAcpBridge.test.ts
index e7e9ee78753c..a564a711a2f6 100644
--- a/apps/server/src/mcp/AcpMcpOverAcpBridge.test.ts
+++ b/apps/server/src/mcp/AcpMcpOverAcpBridge.test.ts
@@ -1,5 +1,4 @@
 // The bridge intentionally treats MCP JSON-RPC messages as opaque JSON.
-// @effect-diagnostics preferSchemaOverJson:off
 import { describe, expect, it } from "@effect/vitest";
 import * as Effect from "effect/Effect";
 import * as Fiber from "effect/Fiber";
diff --git a/apps/server/src/mcp/AcpMcpStdioBridge.test.ts b/apps/server/src/mcp/AcpMcpStdioBridge.test.ts
index 654659151a8c..9cde2b880a7a 100644
--- a/apps/server/src/mcp/AcpMcpStdioBridge.test.ts
+++ b/apps/server/src/mcp/AcpMcpStdioBridge.test.ts
@@ -1,6 +1,6 @@
 // The harness asserts raw JSON-RPC wire strings, mirroring the bridge's
 // schema-free passthrough.
-// @effect-diagnostics nodeBuiltinImport:off globalTimers:off preferSchemaOverJson:off
+// @effect-diagnostics nodeBuiltinImport:off globalTimers:off
 import * as NodeStream from "node:stream";
 
 import { describe, expect, it } from "@effect/vitest";
diff --git a/apps/server/src/orchestration-v2/ProjectStore.test.ts b/apps/server/src/orchestration-v2/ProjectStore.test.ts
index 23884a0ec54f..77cc0fda60e2 100644
--- a/apps/server/src/orchestration-v2/ProjectStore.test.ts
+++ b/apps/server/src/orchestration-v2/ProjectStore.test.ts
@@ -44,7 +44,6 @@ it.layer(ProjectStore.layer.pipe(Layer.provideMerge(SqlitePersistence.layerMemor
           FROM projection_projects
           WHERE project_id = ${projectId}
         `;
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         assert.strictEqual(rows[0]?.defaultModelSelection, JSON.stringify(modelSelection));
         assert.deepStrictEqual(
           Option.getOrNull(yield* projects.get(projectId))?.defaultModelSelection,
diff --git a/apps/server/src/persistence/Migrations/016_CanonicalizeModelSelections.test.ts b/apps/server/src/persistence/Migrations/016_CanonicalizeModelSelections.test.ts
index 78624fa13709..9c20724c55d3 100644
--- a/apps/server/src/persistence/Migrations/016_CanonicalizeModelSelections.test.ts
+++ b/apps/server/src/persistence/Migrations/016_CanonicalizeModelSelections.test.ts
@@ -265,7 +265,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
         FROM orchestration_events
         ORDER BY rowid ASC
       `;
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[0]!.payloadJson), {
             projectId: "project-1",
             title: "Project",
@@ -281,7 +280,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             createdAt: "2026-01-01T00:00:00.000Z",
             updatedAt: "2026-01-01T00:00:00.000Z",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[1]!.payloadJson), {
             projectId: "project-2",
             title: "Fallback Project",
@@ -297,7 +295,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             createdAt: "2026-01-01T00:00:00.000Z",
             updatedAt: "2026-01-01T00:00:00.000Z",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[2]!.payloadJson), {
             projectId: "project-3",
             title: "Null Model Project",
@@ -307,7 +304,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             createdAt: "2026-01-01T00:00:00.000Z",
             updatedAt: "2026-01-01T00:00:00.000Z",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[3]!.payloadJson), {
             threadId: "thread-1",
             projectId: "project-1",
@@ -327,7 +323,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             createdAt: "2026-01-01T00:00:00.000Z",
             updatedAt: "2026-01-01T00:00:00.000Z",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[4]!.payloadJson), {
             threadId: "thread-2",
             projectId: "project-1",
@@ -346,7 +341,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             createdAt: "2026-01-01T00:00:00.000Z",
             updatedAt: "2026-01-01T00:00:00.000Z",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[5]!.payloadJson), {
             threadId: "thread-1",
             turnId: "turn-1",
@@ -360,7 +354,6 @@ layer("016_CanonicalizeModelSelections", (it) => {
             },
             deliveryMode: "buffered",
           });
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           assert.deepStrictEqual(JSON.parse(eventRows[6]!.payloadJson), {
             threadId: "thread-3",
             projectId: "project-1",
diff --git a/apps/server/src/provider/ClaudeCapabilitiesProbe.test.ts b/apps/server/src/provider/ClaudeCapabilitiesProbe.test.ts
index 8147a43b05a5..831df2d172ec 100644
--- a/apps/server/src/provider/ClaudeCapabilitiesProbe.test.ts
+++ b/apps/server/src/provider/ClaudeCapabilitiesProbe.test.ts
@@ -293,7 +293,6 @@ it.layer(NodeServices.layer)("Claude capability probe SDK boundary", (it) => {
         },
       });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const invocation = JSON.parse(yield* fs.readFileString(invocationPath)) as {
         readonly args: ReadonlyArray<string>;
         readonly cwd: string;
@@ -310,7 +309,6 @@ it.layer(NodeServices.layer)("Claude capability probe SDK boundary", (it) => {
 
       const settingsFlagIndex = invocation.args.indexOf("--settings");
       assert.notEqual(settingsFlagIndex, -1);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const flagSettings = JSON.parse(invocation.args[settingsFlagIndex + 1] ?? "{}") as {
         readonly disableAllHooks?: boolean;
       };
diff --git a/apps/server/src/provider/CodexChatGptAuth.test.ts b/apps/server/src/provider/CodexChatGptAuth.test.ts
index fc840d029b99..96465947b651 100644
--- a/apps/server/src/provider/CodexChatGptAuth.test.ts
+++ b/apps/server/src/provider/CodexChatGptAuth.test.ts
@@ -1,4 +1,4 @@
-// @effect-diagnostics nodeBuiltinImport:off globalFetchInEffect:off preferSchemaOverJson:off - Local mock OAuth server validates the browser callback boundary.
+// @effect-diagnostics nodeBuiltinImport:off globalFetchInEffect:off - Local mock OAuth server validates the browser callback boundary.
 import * as NodeHttp from "node:http";
 import * as NodeCrypto from "node:crypto";
 import * as NodeServices from "@effect/platform-node/NodeServices";
diff --git a/apps/server/src/provider/CodexChatGptModels.test.ts b/apps/server/src/provider/CodexChatGptModels.test.ts
index 736f1319d7f0..9533a3c64d00 100644
--- a/apps/server/src/provider/CodexChatGptModels.test.ts
+++ b/apps/server/src/provider/CodexChatGptModels.test.ts
@@ -1,4 +1,3 @@
-// @effect-diagnostics preferSchemaOverJson:off - Mock HTTP responses use JSON fixtures.
 import { assert, it } from "@effect/vitest";
 import * as Effect from "effect/Effect";
 import { HttpClient, HttpClientResponse } from "effect/http";
diff --git a/apps/server/src/provider/GrokProvider.test.ts b/apps/server/src/provider/GrokProvider.test.ts
index 7a01812c6833..f77ee10465e2 100644
--- a/apps/server/src/provider/GrokProvider.test.ts
+++ b/apps/server/src/provider/GrokProvider.test.ts
@@ -380,7 +380,6 @@ it.layer(NodeServices.layer)("checkGrokProviderStatus", (it) => {
             directory: dir,
             name: "grok",
             source: [
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               `process.stderr.write(${JSON.stringify(`${secretStderr}\n`)});`,
               "process.exit(2);",
               "",
@@ -417,7 +416,6 @@ it.layer(NodeServices.layer)("checkGrokProviderStatus", (it) => {
           "  process.exit(0);",
           "}",
           'if (process.argv[2] === "models") {',
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           `  process.stdout.write(${JSON.stringify(input.modelsOutput)});`,
           "  process.exit(0);",
           "}",
diff --git a/apps/server/src/provider/ProviderInstanceRegistry.test.ts b/apps/server/src/provider/ProviderInstanceRegistry.test.ts
index d78de9ecf44e..7a132b40fc88 100644
--- a/apps/server/src/provider/ProviderInstanceRegistry.test.ts
+++ b/apps/server/src/provider/ProviderInstanceRegistry.test.ts
@@ -172,7 +172,6 @@ const makeTildeProviderFixtures = Effect.fn(
   );
   yield* fileSystem.writeFileString(
     codexScriptPath,
-    // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed script document read by the external Codex mock peer.
     JSON.stringify({ rootThreadId: "probe-thread", notifications: [] }),
   );
   yield* fileSystem.chmod(codexPath, 0o755);
@@ -346,7 +345,6 @@ describe("ProviderInstanceRegistry — multi-instance codex slice", () => {
       const fixtures = yield* makeTildeProviderFixtures();
       yield* fileSystem.writeFileString(
         fixtures.codexScriptPath,
-        // @effect-diagnostics-next-line preferSchemaOverJson:off - fixed script document read by the external Codex mock peer.
         JSON.stringify({
           rootThreadId: "probe-thread",
           notifications: [],
diff --git a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
index a6824d8a0a13..be8354c6444c 100644
--- a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
+++ b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
@@ -228,7 +228,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         ...row,
         description: "x".repeat(10_000),
       }));
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const response = JSON.stringify(rows);
       expect(Buffer.byteLength(response)).toBeGreaterThan(1_000_000);
 
@@ -341,7 +340,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         .mockReturnValueOnce(
           Effect.succeed(
             output(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify([
                 { pullRequestId: "malformed" },
                 pullRequestRows(1, 1)[0],
@@ -434,7 +432,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
     Effect.gen(function* () {
       // `--query user` unwraps the object, so the wrapper has to put it back.
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ name: "bilal@acme.dev", type: "user" }))),
       );
       const cli = yield* AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli;
@@ -636,7 +633,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         .mockReturnValueOnce(
           Effect.succeed(
             output(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify({
                 pullRequestId: 42,
                 title: "Add the page",
@@ -653,7 +649,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         .mockReturnValueOnce(
           Effect.succeed(
             output(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify({
                 value: [
                   {
@@ -674,7 +669,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         .mockReturnValueOnce(
           Effect.succeed(
             output(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify({
                 changeEntries: [
                   { changeType: "edit", item: { path: "/README.md", objectId: "8f80" } },
@@ -713,7 +707,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
       // pull request read every time they checked whether a file had been pushed to.
       const pullRequest = Effect.succeed(
         output(
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           JSON.stringify({
             pullRequestId: 42,
             title: "Add the page",
@@ -1219,7 +1212,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               value: [
                 {
@@ -1374,7 +1366,6 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
         Effect.succeed(
           output(
             // Well-formed, but with nothing to build a link from: not a decode failure.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               pullRequestId: 42,
               title: "Add the page",
diff --git a/apps/server/src/pullRequest/BitbucketPullRequestApi.test.ts b/apps/server/src/pullRequest/BitbucketPullRequestApi.test.ts
index 49cdaa90f7d2..d614dd90a7e7 100644
--- a/apps/server/src/pullRequest/BitbucketPullRequestApi.test.ts
+++ b/apps/server/src/pullRequest/BitbucketPullRequestApi.test.ts
@@ -676,7 +676,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       expect(call.method).toBe("PUT");
       expect(call.url).toBe("/repositories/acme/web/pullrequests/7");
       // Bitbucket's PUT is a partial update, so a field left out of the body is left as it was.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(call.body ?? "")).toEqual({ title: "A new title" });
     }),
   );
@@ -688,7 +687,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
 
       yield* api.updateChangeRequest({ repository: "acme/web", number: 7, body: "New body." });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).body ?? "")).toEqual({ description: "New body." });
     }),
   );
@@ -705,7 +703,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
         body: "New body.",
       });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).body ?? "")).toEqual({
         title: "A new title",
         description: "New body.",
@@ -736,7 +733,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
   it.effect("fails the read when Bitbucket answers with something unreadable", () =>
     Effect.gen(function* () {
       mockedRequest.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(response(JSON.stringify({ error: "nope" }))),
       );
       const api = yield* BitbucketPullRequestApi.BitbucketPullRequestApi;
@@ -769,7 +765,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
 
   it.effect("fails when the credentials belong to no named account", () =>
     Effect.gen(function* () {
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       mockedRequest.mockReturnValueOnce(Effect.succeed(response(JSON.stringify({}))));
       const api = yield* BitbucketPullRequestApi.BitbucketPullRequestApi;
 
@@ -784,7 +779,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       mockedRequest.mockReturnValueOnce(
         Effect.succeed(
           response(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               next: "https://api.bitbucket.org/2.0/comments?page=2",
               values: [
@@ -805,7 +799,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
           response(
             // The reply arrives a page after the remark it answers, which is why the threads
             // are only assembled once every page is in hand.
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               values: [
                 {
@@ -840,7 +833,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       mockedRequest.mockReturnValue(
         Effect.succeed(
           response(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               next: "https://api.bitbucket.org/2.0/comments?page=2",
               values: [
@@ -868,7 +860,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       mockedRequest.mockReturnValueOnce(
         Effect.succeed(
           response(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               values: [
                 {
@@ -941,7 +932,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       });
 
       expect(callAt(0).url).toContain("/pullrequests/7/comments");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).body ?? "")).toEqual({
         content: { raw: "why remove?" },
         inline: { path: "src/a.ts", from: 12 },
@@ -988,7 +978,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
         body: "Fixed.",
       });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).body ?? "")).toEqual({
         content: { raw: "Fixed." },
         parent: { id: 10 },
@@ -1001,7 +990,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       mockedRequest.mockReturnValue(
         Effect.succeed(
           response(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({ values: [{ type: "repository_permission", permission: "read" }] }),
           ),
         ),
@@ -1017,7 +1005,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
 
   it.effect("escapes a repository name before it goes inside a filter literal", () =>
     Effect.gen(function* () {
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       mockedRequest.mockReturnValue(Effect.succeed(response(JSON.stringify({ values: [] }))));
       const api = yield* BitbucketPullRequestApi.BitbucketPullRequestApi;
 
@@ -1075,7 +1062,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
         .mockReturnValueOnce(
           Effect.succeed(
             response(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify({ values: [{ user: bilal }, { user: octocat }, { user: hubot }] }),
             ),
           ),
@@ -1113,7 +1099,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       const call = callAt(1);
       expect(call.method).toBe("PUT");
       expect(call.url).toBe("/repositories/acme/web/pullrequests/7");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(call.body ?? "")).toEqual({
         reviewers: [{ uuid: "{octocat}" }, { uuid: "{hubot}" }],
       });
@@ -1136,7 +1121,6 @@ layer("BitbucketPullRequestApi.layer", (it) => {
         requested: false,
       });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(1).body ?? "")).toEqual({ reviewers: [{ uuid: "{octocat}" }] });
     }),
   );
diff --git a/apps/server/src/pullRequest/GitHubPullRequestCli.test.ts b/apps/server/src/pullRequest/GitHubPullRequestCli.test.ts
index 7e6146834db8..28aca8b6a9b3 100644
--- a/apps/server/src/pullRequest/GitHubPullRequestCli.test.ts
+++ b/apps/server/src/pullRequest/GitHubPullRequestCli.test.ts
@@ -789,7 +789,6 @@ layer("GitHubPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               data: { w0: { pullRequest: node(1) }, w1: { pullRequest: null } },
             }),
diff --git a/apps/server/src/pullRequest/GitLabPullRequestCli.test.ts b/apps/server/src/pullRequest/GitLabPullRequestCli.test.ts
index 76fb1059b91d..8fb1334de364 100644
--- a/apps/server/src/pullRequest/GitLabPullRequestCli.test.ts
+++ b/apps/server/src/pullRequest/GitLabPullRequestCli.test.ts
@@ -226,10 +226,8 @@ layer("GitLabPullRequestCli.layer", (it) => {
 
   it.effect("advances the cursor through malformed raw rows", () =>
     Effect.gen(function* () {
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const rows = JSON.parse(mergeRequests(2, 1)) as ReadonlyArray<unknown>;
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify([{ iid: "malformed" }, ...rows]))),
       );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
@@ -314,7 +312,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
     Effect.gen(function* () {
       // Full pages of unusable rows: nothing is collected, so the collected-count bound never
       // trips and only the page bound can end the walk.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const unusable = JSON.stringify(Array.from({ length: 100 }, () => ({ iid: "nope" })));
       mockedExecute.mockReturnValue(Effect.succeed(output(unusable)));
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
@@ -627,7 +624,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("reports a commit with no parent as a structured error", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ id: "a1b2c3d", parent_ids: [] }))),
       );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
@@ -654,7 +650,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("expands a new file from a root commit without requiring a parent", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ id: "a1b2c3d", parent_ids: [] }))),
       );
       mockedExecute.mockReturnValueOnce(Effect.succeed(output("first contents\n")));
@@ -680,7 +675,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               diff_refs: {
                 base_sha: "a1b2c3d",
@@ -718,7 +712,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               diff_refs: {
                 base_sha: "a1b2c3d",
@@ -758,7 +751,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               diff_refs: {
                 base_sha: "a1b2c3d",
@@ -823,7 +815,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("offers no squash when the project does not say it allows one", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ merge_method: "merge" }))),
       );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
@@ -840,7 +831,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("reads the project's merge settings as its merge capabilities", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ merge_method: "ff", squash_option: "never" }))),
       );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
@@ -884,7 +874,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
 
   it.effect("fails when the authenticated account has no username", () =>
     Effect.gen(function* () {
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       mockedExecute.mockReturnValueOnce(Effect.succeed(output(JSON.stringify({ username: "" }))));
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
 
@@ -935,7 +924,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 id: "abc123",
@@ -994,7 +982,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 7,
               title: "t",
@@ -1030,7 +1017,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       // The diff revisions first, because a positioned comment cannot be placed without them.
       expect(argsOfCall(0)[1]).toContain("merge_requests/7");
       expect(argsOfCall(1)[1]).toContain("/discussions");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(1).stdin ?? "")).toEqual({
         body: "why remove?",
         position: {
@@ -1086,7 +1072,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       expect(argsOfCall(0)).toContain("--method");
       expect(argsOfCall(0)).toContain("PUT");
       expect(argsOfCall(0)[1]).toContain("/discussions/abc123");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).stdin ?? "")).toEqual({ resolved: true });
     }),
   );
@@ -1117,13 +1102,11 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("removes an award by listing them and deleting the reader's own id", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ username: "bilal" }))),
       );
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               { id: 5, name: "thumbsup", user: { username: "bilal" } },
               { id: 6, name: "thumbsup", user: { username: "julius" } },
@@ -1155,7 +1138,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
   it.effect("does nothing when the reader has no award of that name to take back", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         Effect.succeed(output(JSON.stringify({ username: "bilal" }))),
       );
       mockedExecute.mockReturnValueOnce(Effect.succeed(output("[]")));
@@ -1179,7 +1161,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 7,
               title: "t",
@@ -1217,10 +1198,7 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute
         .mockReturnValueOnce(Effect.succeed(output(mergeRequestJson({ reviewers: [reviewer] }))))
         .mockReturnValueOnce(
-          Effect.succeed(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
-            output(JSON.stringify([author, reviewer, { id: 9, username: "hubot" }])),
-          ),
+          Effect.succeed(output(JSON.stringify([author, reviewer, { id: 9, username: "hubot" }]))),
         );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
 
@@ -1258,7 +1236,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       // GitLab replaces the whole set, so the reviewer already on the merge request has to be
       // sent back with the new one or the request would take them off it.
       expect(argsOfCall(1)).toContain("PUT");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(1).stdin ?? "")).toEqual({ reviewer_ids: [5, 9] });
     }),
   );
@@ -1282,7 +1259,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
         requested: false,
       });
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(1).stdin ?? "")).toEqual({ reviewer_ids: [5] });
     }),
   );
@@ -1303,7 +1279,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       });
 
       // Sending it as a number would rewrite the reviewer set around something nobody chose.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(1).stdin ?? "")).toEqual({ reviewer_ids: [5] });
     }),
   );
@@ -1330,7 +1305,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
         "--header",
         "Content-Type: application/json",
       ]);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).stdin ?? "")).toEqual({ title: "A better title" });
     }),
   );
@@ -1348,7 +1322,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       });
 
       // A title sent as an empty string would wipe the one the merge request already has.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).stdin ?? "")).toEqual({ description: "What this changes." });
     }),
   );
@@ -1367,7 +1340,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       });
 
       assert.strictEqual(mockedExecute.mock.calls.length, 1);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(callAt(0).stdin ?? "")).toEqual({
         title: "A better title",
         description: "What this changes.",
@@ -1407,7 +1379,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 7,
               title: "t",
@@ -1424,7 +1395,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               data: {
                 project: { repository: { blobs: { nodes: [{ path: "src/a.ts", oid: "aaa" }] } } },
@@ -1449,7 +1419,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
         ["src/gone.ts", ""],
       ]);
       // The head the reader is looking at, not whatever the source branch has moved on to.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const body: unknown = JSON.parse(callAt(1).stdin ?? "{}");
       expect(body).toMatchObject({
         variables: { fullPath: "acme/web", ref: "head", paths: ["src/a.ts", "src/gone.ts"] },
@@ -1462,7 +1431,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 7,
               title: "t",
@@ -1480,10 +1448,7 @@ layer("GitLabPullRequestCli.layer", (it) => {
       // these files, and reading it that way would report every file the reader has cleared as
       // changed on nothing worse than a permission.
       mockedExecute.mockReturnValueOnce(
-        Effect.succeed(
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
-          output(JSON.stringify({ data: { project: null } })),
-        ),
+        Effect.succeed(output(JSON.stringify({ data: { project: null } }))),
       );
       const cli = yield* GitLabPullRequestCli.GitLabPullRequestCli;
 
@@ -1520,7 +1485,6 @@ layer("GitLabPullRequestCli.layer", (it) => {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
           output(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 7,
               title: "t",
diff --git a/apps/server/src/serverSettings.test.ts b/apps/server/src/serverSettings.test.ts
index 59f188d7d1b5..44ce0767e4b4 100644
--- a/apps/server/src/serverSettings.test.ts
+++ b/apps/server/src/serverSettings.test.ts
@@ -578,7 +578,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
         const change = Option.getOrUndefined(yield* Stream.runHead(changes));
         const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
         // Inspect raw persisted JSON before schema decoding can apply defaults.
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
         const persisted = JSON.parse(raw) as Record<string, unknown>;
 
         assert.strictEqual(next.sidebarAutoSettleAfterDays, null);
@@ -759,7 +758,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
 
         const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
         assert.deepEqual(
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           JSON.parse(raw).sourceControlWriterModelSelection,
           sourceControlWriterModelSelection,
         );
@@ -1046,7 +1044,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
       assert.isFalse(settings.providers.grok.enabled);
 
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       assert.isFalse(JSON.parse(raw).providers.grok.enabled);
     }).pipe(Effect.provide(layerServerSettings())),
   );
@@ -1067,7 +1064,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
       yield* serverSettings.updateSettings({ addProjectBaseDirectory: "~/Development" });
 
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const persisted = JSON.parse(raw);
       assert.isTrue(persisted.providers.cursor.enabled);
       assert.isTrue(persisted.providers.grok.enabled);
@@ -1104,7 +1100,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
       assert.isFalse(resolveProviderInstanceEnabled(grok));
 
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       const persisted = JSON.parse(raw);
       assert.isFalse(persisted.providers.cursor.enabled);
       assert.isFalse(persisted.providers.grok.enabled);
@@ -1288,7 +1283,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
       assert.equal(next.providers.codex.binaryPath, "/opt/homebrew/bin/codex");
 
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       assert.deepEqual(JSON.parse(raw), {
         addProjectBaseDirectory: "~/Development",
         observability: {
@@ -1506,7 +1500,6 @@ it.layer(NodeServices.layer)("server settings", (it) => {
 
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
       assert.notInclude(raw, "sk-or-secret");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       assert.deepEqual(JSON.parse(raw).providerInstances.codex_personal.environment, [
         {
           name: "OPENROUTER_API_KEY",
@@ -1992,10 +1985,7 @@ it.layer(NodeServices.layer)("server settings", (it) => {
         projectSettingsOverrides: { [legacyProject]: null },
       });
       const raw = yield* fileSystem.readFileString(serverConfig.settingsPath);
-      const persisted = yield* decodeServerSettings(
-        // @effect-diagnostics-next-line preferSchemaOverJson:off
-        JSON.parse(raw),
-      );
+      const persisted = yield* decodeServerSettings(JSON.parse(raw));
       assert.isTrue(persisted.projectSettingsFolded);
       assert.isUndefined(persisted.projectSettingsOverrides[legacyProject]);
     }).pipe(Effect.provide(layerServerSettings())),
diff --git a/apps/server/src/serviceLauncher.test.ts b/apps/server/src/serviceLauncher.test.ts
index 30b239f3e47f..df2ab9e9cd06 100644
--- a/apps/server/src/serviceLauncher.test.ts
+++ b/apps/server/src/serviceLauncher.test.ts
@@ -198,7 +198,6 @@ it.layer(NodeServices.layer)("service state persistence", (it) => {
       const databasePath = path.join(root, "userdata", "state.sqlite");
       yield* fs.makeDirectory(path.dirname(databasePath), { recursive: true });
       yield* fs.writeFileString(databasePath, "before trial");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - embeds a path in fake child source.
       const encodedDatabasePath = JSON.stringify(databasePath);
       const childSource = `
 const context = JSON.parse(process.env.T3_SERVICE_LAUNCHER_CONTEXT);
@@ -252,7 +251,6 @@ if (context.update?.status === "pending") {
       const databasePath = path.join(root, "userdata", "state.sqlite");
       yield* fs.makeDirectory(path.dirname(databasePath), { recursive: true });
       yield* fs.writeFileString(databasePath, "before trial");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - embeds a path in fake child source.
       const encodedDatabasePath = JSON.stringify(databasePath);
       const childSource = `
 const context = JSON.parse(process.env.T3_SERVICE_LAUNCHER_CONTEXT);
@@ -308,7 +306,6 @@ if (context.update?.status === "pending") {
       const original = "database before migration";
       yield* fs.makeDirectory(path.dirname(databasePath), { recursive: true });
       yield* fs.writeFileString(databasePath, original);
-      // @effect-diagnostics-next-line preferSchemaOverJson:off - embeds a path in fake child source.
       const encodedDatabasePath = JSON.stringify(databasePath);
       const childSource = `
 import { writeFileSync } from "node:fs";
diff --git a/apps/server/src/sourceControl/AzureDevOpsCli.test.ts b/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
index 6ef0b35559fd..249397824609 100644
--- a/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
+++ b/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
@@ -39,7 +39,6 @@ describe("AzureDevOpsCli.layer", () => {
       mockRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               pullRequestId: 42,
               title: "Add Azure provider",
@@ -97,7 +96,6 @@ describe("AzureDevOpsCli.layer", () => {
       mockRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               pullRequestId: 863,
               title: "Fix Azure link",
@@ -134,7 +132,6 @@ describe("AzureDevOpsCli.layer", () => {
       mockRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 pullRequestId: 7,
@@ -195,7 +192,6 @@ describe("AzureDevOpsCli.layer", () => {
       mockRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               name: "repo",
               webUrl: "https://dev.azure.com/acme/project/_git/repo",
@@ -228,7 +224,6 @@ describe("AzureDevOpsCli.layer", () => {
       mockRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               name: "repo",
               webUrl: "https://dev.azure.com/acme/project/_git/repo",
diff --git a/apps/server/src/sourceControl/BitbucketApi.test.ts b/apps/server/src/sourceControl/BitbucketApi.test.ts
index 2ea48c3fdc8c..352bfc60d970 100644
--- a/apps/server/src/sourceControl/BitbucketApi.test.ts
+++ b/apps/server/src/sourceControl/BitbucketApi.test.ts
@@ -541,7 +541,6 @@ it.effect("creates repositories through the Bitbucket REST API", () => {
     assert.ok(request);
     const rawBody = (request.body as { readonly body?: Uint8Array }).body;
     assert.ok(rawBody);
-    // @effect-diagnostics-next-line preferSchemaOverJson:off
     assert.deepStrictEqual(JSON.parse(new TextDecoder().decode(rawBody)), {
       scm: "git",
       is_private: true,
@@ -577,7 +576,6 @@ it.effect("creates pull requests using the official REST payload shape", () => {
     assert.ok(request);
     const rawBody = (request.body as { readonly body?: Uint8Array }).body;
     assert.ok(rawBody);
-    // @effect-diagnostics-next-line preferSchemaOverJson:off
     assert.deepStrictEqual(JSON.parse(new TextDecoder().decode(rawBody)), {
       title: "Provider PR",
       description: "PR body",
diff --git a/apps/server/src/sourceControl/GitLabCli.test.ts b/apps/server/src/sourceControl/GitLabCli.test.ts
index a87a32831098..5a10f13b8f8f 100644
--- a/apps/server/src/sourceControl/GitLabCli.test.ts
+++ b/apps/server/src/sourceControl/GitLabCli.test.ts
@@ -39,7 +39,6 @@ layer("GitLabCli.layer", (it) => {
       mockedRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               iid: 42,
               title: "Add MR thread creation",
@@ -94,7 +93,6 @@ layer("GitLabCli.layer", (it) => {
       mockedRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify([
               {
                 iid: 0,
@@ -163,7 +161,6 @@ layer("GitLabCli.layer", (it) => {
       mockedRun.mockReturnValueOnce(
         Effect.succeed(
           processOutput(
-            // @effect-diagnostics-next-line preferSchemaOverJson:off
             JSON.stringify({
               path_with_namespace: "octocat/t3code",
               web_url: "https://gitlab.com/octocat/t3code",
@@ -230,18 +227,10 @@ layer("GitLabCli.layer", (it) => {
     Effect.gen(function* () {
       mockedRun
 
+        .mockReturnValueOnce(Effect.succeed(processOutput(JSON.stringify({ id: 1234 }))))
         .mockReturnValueOnce(
           Effect.succeed(
             processOutput(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
-              JSON.stringify({ id: 1234 }),
-            ),
-          ),
-        )
-        .mockReturnValueOnce(
-          Effect.succeed(
-            processOutput(
-              // @effect-diagnostics-next-line preferSchemaOverJson:off
               JSON.stringify({
                 path_with_namespace: "octocat/t3code",
                 web_url: "https://gitlab.com/octocat/t3code",
diff --git a/apps/server/src/textGeneration/ClaudeTextGeneration.test.ts b/apps/server/src/textGeneration/ClaudeTextGeneration.test.ts
index b373973b4944..0ee4b8763cfc 100644
--- a/apps/server/src/textGeneration/ClaudeTextGeneration.test.ts
+++ b/apps/server/src/textGeneration/ClaudeTextGeneration.test.ts
@@ -367,7 +367,6 @@ it.layer(layerClaudeTextGenerationTest)("ClaudeTextGeneration", (it) => {
       const claudeConfigDir = path.join(process.cwd(), ".claude-work-test");
       return yield* withFakeClaudeEnv(
         {
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           output: JSON.stringify({
             structured_output: {
               title: "Use Claude home",
diff --git a/apps/server/src/vcs/VcsProjectConfig.test.ts b/apps/server/src/vcs/VcsProjectConfig.test.ts
index f28d3eb51452..1c91cbadea8c 100644
--- a/apps/server/src/vcs/VcsProjectConfig.test.ts
+++ b/apps/server/src/vcs/VcsProjectConfig.test.ts
@@ -42,7 +42,6 @@ describe("VcsProjectConfig", () => {
         yield* fileSystem.makeDirectory(nested, { recursive: true });
         yield* fileSystem.writeFileString(
           path.join(configDir, "vcs.json"),
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           JSON.stringify({ vcs: { kind: "jj" } }),
         );
 
@@ -72,7 +71,6 @@ describe("VcsProjectConfig", () => {
         yield* fileSystem.makeDirectory(configDir, { recursive: true });
         yield* fileSystem.writeFileString(
           path.join(configDir, "vcs.json"),
-          // @effect-diagnostics-next-line preferSchemaOverJson:off
           JSON.stringify({ vcs: { kind: "jj" } }),
         );
 
diff --git a/apps/web/src/cloud/linkEnvironment.test.ts b/apps/web/src/cloud/linkEnvironment.test.ts
index cb775c26ff6a..dbcaacfa25a4 100644
--- a/apps/web/src/cloud/linkEnvironment.test.ts
+++ b/apps/web/src/cloud/linkEnvironment.test.ts
@@ -240,7 +240,6 @@ describe("web cloud link environment client", () => {
         "http://127.0.0.1:3000/api/connect/preferences",
       );
       expect(fetchMock.mock.calls[0]?.[1]?.method).toBe("POST");
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(bodyText(fetchMock.mock.calls[0]?.[1]?.body))).toEqual({
         publishAgentActivity: true,
       });
@@ -290,7 +289,6 @@ describe("web cloud link environment client", () => {
       expect(String(fetchMock.mock.calls[1]?.[0])).toBe(
         "http://127.0.0.1:3000/api/connect/link-proof",
       );
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(bodyText(fetchMock.mock.calls[1]?.[1]?.body))).toMatchObject({
         challenge: "challenge",
         endpoint: {
@@ -341,11 +339,9 @@ describe("web cloud link environment client", () => {
         }),
       );
 
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(bodyText(fetchMock.mock.calls[0]?.[1]?.body))).toMatchObject({
         managedTunnelsEnabled: false,
       });
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(bodyText(fetchMock.mock.calls[1]?.[1]?.body))).toMatchObject({
         endpoint: { providerKind: "manual" },
       });
diff --git a/packages/client-runtime/src/state/pullRequestDiffHttp.test.ts b/packages/client-runtime/src/state/pullRequestDiffHttp.test.ts
index b69aeaab3855..849553e89359 100644
--- a/packages/client-runtime/src/state/pullRequestDiffHttp.test.ts
+++ b/packages/client-runtime/src/state/pullRequestDiffHttp.test.ts
@@ -71,7 +71,6 @@ describe("fetchEnvironmentPullRequestDiff", () => {
             : "";
       // The assertion deliberately inspects the serialized wire body rather than decoding a
       // domain value for use in application code.
-      // @effect-diagnostics-next-line preferSchemaOverJson:off
       expect(JSON.parse(body)).toEqual({
         projectId: "project-1",
         repository: "owner/repository",
diff --git a/tsconfig.base.json b/tsconfig.base.json
index 61f331a128f9..f6914a8e1e6c 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -51,7 +51,13 @@
           "globalFetch": "error",
           "globalFetchInEffect": "error",
           "schemaNumber": "off"
-        }
+        },
+        "overrides": [
+          {
+            "include": ["**/*.test.ts", "**/*.test.tsx"],
+            "options": { "diagnosticSeverity": { "preferSchemaOverJson": "off" } }
+          }
+        ]
       }
     ]
   }