diff --git a/EVENTS.md b/EVENTS.md
index 1a73b10..40d5435 100644
--- a/EVENTS.md
+++ b/EVENTS.md
@@ -92,7 +92,7 @@ Emitted when extended thinking content is complete (requires `--thinking` flag).
 
 ### `tool_use`
 
-Emitted when a tool call completes (success or error).
+Emitted when a tool call completes (success or error). This includes tools executed within subagent sessions.
 
 ```json
 {
@@ -100,6 +100,7 @@ Emitted when a tool call completes (success or error).
   "part": {
     "type": "tool",
     "tool": "bash",
+    "sessionID": "session_01abc...",
     "state": {
       "status": "completed",
       "input": { "command": "ls" },
@@ -111,6 +112,8 @@ Emitted when a tool call completes (success or error).
 
 `state.status` is `"completed"` or `"error"`. On error, `state.error` contains the error message.
 
+For tools executed inside a subagent, `part.sessionID` will differ from the top-level `sessionID` — compare the two to identify subagent tool calls.
+
 ### `step_start` / `step_finish`
 
 Emitted at step boundaries during multi-step tool use.
diff --git a/packages/cli/src/cli/cmd/run.ts b/packages/cli/src/cli/cmd/run.ts
index ddf1fe7..8679e6b 100644
--- a/packages/cli/src/cli/cmd/run.ts
+++ b/packages/cli/src/cli/cmd/run.ts
@@ -475,7 +475,19 @@ export const RunCommand = cmd({
 
           if (event.type === "message.part.updated") {
             const part = event.properties.part
-            if (part.sessionID !== sessionID) continue
+
+            // Skip non-primary session events, but emit tool_use for subagent sessions in JSON mode
+            if (part.sessionID !== sessionID) {
+              if (
+                args.format === "json" &&
+                childSessions.has(part.sessionID) &&
+                part.type === "tool" &&
+                (part.state.status === "completed" || part.state.status === "error")
+              ) {
+                emit("tool_use", { part })
+              }
+              continue
+            }
 
             if (part.type === "tool" && (part.state.status === "completed" || part.state.status === "error")) {
               if (emit("tool_use", { part })) continue