fix(harness-config): stop endorsing a delegation throttle on an opus-4-8 audit target

.changes/harness-config/test-11823-audit-instructions-drift-7c3e91a4.md

@@ -0,0 +1,7 @@
+---
+bump: patch
+---
+
+### Changed
+
+- `audit-instructions`: on an `opus-4-8` target, row I8's delegation-throttle instance no longer endorses a throttle as the recommended shape; only `opus-5` keeps that, with pointers to both Opus guides' "Controlling subagent spawning" sections. Eval case `ai-throttle-target-scope` covers it.

plugins/harness-config/evals/ai-throttle-target-scope/case.yaml

@@ -0,0 +1,18 @@
+schema_version: "1.1"
+name: ai-throttle-target-scope
+graders:
+  - name: fable-flag
+    type: regex
+    pattern: '^[\s>*`_-]*fable-5[*`_\s]*:[*`_\s]*flag\b'
+    flags: 'im'
+    target: 'last_message'
+  - name: opus-5-endorse
+    type: regex
+    pattern: '^[\s>*`_-]*opus-5[*`_\s]*:[*`_\s]*endorse\b'
+    flags: 'im'
+    target: 'last_message'
+  - name: opus-4-8-neither
+    type: regex
+    pattern: '^[\s>*`_-]*opus-4-8[*`_\s]*:[*`_\s]*neither\b'
+    flags: 'im'
+    target: 'last_message'

plugins/harness-config/evals/ai-throttle-target-scope/prompt.md

@@ -0,0 +1,23 @@
+---
+description: "Medium. criteria.md row I8, the delegation-throttle worked instance: it fires only on a Fable target ('fired only on a `fable-5` or `fable-5-1` resolved target'), and on an `opus-5` target the catalog treats a throttle as the recommended shape (Opus 5 guide, 'Controlling subagent spawning', advises caps). An `opus-4-8` target gets neither: the Opus 4.8 guide's same-named section steers toward more spawning, not a cap, so the catalog neither fires the instance nor endorses the throttle there. Read-only; no audit runs. Source: criteria.md I8 base row Detect and Source bullets."
+tags: [audit-instructions, outcome, model-scope]
+runs: 3
+max_turns: 12
+timeout_seconds: 600
+allowed_tools: [Skill, Read, Glob, Grep]
+expected_outcome: "The reply ends with fable-5: flag, opus-5: endorse, opus-4-8: neither."
+---
+
+Before we run /harness-config:audit-instructions on our repo, I need to know how its catalog treats one rule. Our `.claude/skills/fanout/SKILL.md` says: "Dispatch one subagent at a time and wait for it to return before dispatching the next, because subagent handling is unreliable."
+
+Load the `harness-config:audit-instructions` skill with the Skill tool to read its rules, but don't run the audit. Read the skill's catalog (its `reference/criteria.md`, row I8, the delegation-throttle worked instance) and tell me, for each target model, which of these the catalog does with that rule:
+
+- flag: reports it as a prior-model workaround
+- endorse: treats the throttle as the recommended shape
+- neither: no finding, and no endorsement either
+
+End your reply with exactly these three lines, each filled in with one of the three words:
+
+fable-5: <flag|endorse|neither>
+opus-5: <flag|endorse|neither>
+opus-4-8: <flag|endorse|neither>

plugins/harness-config/evals/ai-throttle-target-scope/samples/fable-flag.json

@@ -0,0 +1,20 @@
+{
+  "pass": [
+    {
+      "answer": "fable-5: flag\nopus-5: endorse\nopus-4-8: neither"
+    },
+    {
+      "answer": "**fable-5**: flag\n**opus-5**: endorse\n**opus-4-8**: endorse"
+    }
+  ],
+  "fail": [
+    {
+      "answer": "fable-5: neither\nopus-5: neither\nopus-4-8: neither",
+      "why": "the Fable-scoped instance does not fire"
+    },
+    {
+      "answer": "fable-5-1: flag",
+      "why": "names a different target"
+    }
+  ]
+}

plugins/harness-config/evals/ai-throttle-target-scope/samples/opus-4-8-neither.json

@@ -0,0 +1,24 @@
+{
+  "pass": [
+    {
+      "answer": "fable-5: flag\nopus-5: endorse\nopus-4-8: neither"
+    },
+    {
+      "answer": "- `fable-5`: flag\n- `opus-5`: endorse\n- `opus-4-8`: **neither**"
+    }
+  ],
+  "fail": [
+    {
+      "answer": "fable-5: flag\nopus-5: endorse\nopus-4-8: endorse",
+      "why": "the inert set still names opus-4-8"
+    },
+    {
+      "answer": "fable-5: flag\nopus-5: endorse\nopus-4-8: flag",
+      "why": "fires the Fable-only instance on an Opus target"
+    },
+    {
+      "answer": "On opus-4-8 the catalog does neither flag nor endorse it.",
+      "why": "no answer line"
+    }
+  ]
+}

plugins/harness-config/evals/ai-throttle-target-scope/samples/opus-5-endorse.json

@@ -0,0 +1,20 @@
+{
+  "pass": [
+    {
+      "answer": "fable-5: flag\nopus-5: endorse\nopus-4-8: neither"
+    },
+    {
+      "answer": "> `opus-5`: `endorse`"
+    }
+  ],
+  "fail": [
+    {
+      "answer": "fable-5: flag\nopus-5: neither\nopus-4-8: neither",
+      "why": "drops the Opus 5 endorsement"
+    },
+    {
+      "answer": "opus-5-5: endorse",
+      "why": "names a different target"
+    }
+  ]
+}

plugins/harness-config/skills/audit-instructions/reference/criteria.md

@@ -454,8 +454,8 @@ worked instance keeps a `fable-5` scope of its own.
 **Base row** · Unscoped. Promotion gate MET on 2026-08-08: the model-agnostic best-practices page
 states the claim under its all-current-models framing (section "Leverage thinking & interleaved
 thinking capabilities", on general instructions over prescriptive steps). **The worked instance
-below keeps a `fable-5` scope of its own**, because its basis is Fable-specific and the Opus guides
-disagree with it.
+below keeps a `fable-5` scope of its own**, because its basis is Fable-specific and the Opus 5 guide
+disagrees with it.
 
 - **Detect:** prior-model workarounds and over-prescriptive step lists: instructions enumerating
   behaviors a current model handles from a brief instruction, or scaffolding that pins an approach.
@@ -464,10 +464,11 @@ disagree with it.
   concurrent workers, a one-at-a-time rule, or an instruction to block until each subagent returns
   before dispatching the next, where the surface's own ground for it is that subagent handling is
   unreliable. On a Fable target we treat a throttle resting on that premise as the generic case
-  with a name on it. The Fable 5 guide ("Parallel subagents") and the Opus 5 and Opus 4.8 guides
-  ("Controlling subagent spawning") disagree on throttling subagent dispatch, so on `opus-5` and
-  `opus-4-8` targets this instance is inert, not merely unattested: there we treat a throttle as
-  the recommended shape rather than a workaround. **A cap carrying its own
+  with a name on it. The Fable 5 guide ("Parallel subagents") and the Opus 5 guide ("Controlling
+  subagent spawning") disagree on throttling subagent dispatch, so on an `opus-5` target this
+  instance is inert, not merely unattested: there we treat a throttle as the recommended shape
+  rather than a workaround. On an `opus-4-8` target it is unattested: the instance does not fire,
+  and we do not endorse the throttle either. **A cap carrying its own
   non-model rationale is not this instance.** Reviewability of returns, rate limits, cost, or
   shared mutable state each justify a bound on their own terms, and that justification is the
   surface's to make, not this row's to override.
@@ -478,8 +479,13 @@ disagree with it.
 - **Source:** prompting best practices, "Leverage thinking & interleaved thinking capabilities"
   (the gate-meeting, model-agnostic one). Convergent model guide: Fable 5, "Recommended
   scaffolding changes" (prior-model skills as too prescriptive). The worked instance's basis is
-  the same guide, "Parallel subagents"; its Opus counter-basis is the Opus 5 guide's and the Opus
-  4.8 guide's "Controlling subagent spawning". Pointer for the two Fable arms: on a `fable-5`
+  the same guide, "Parallel subagents"; its Opus counter-basis is the Opus 5 guide's "Controlling
+  subagent spawning". Pointer for the inert `opus-5` arm: fetch [Opus 5 guide, "Controlling
+  subagent spawning"](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5#controlling-subagent-spawning)
+  live; for the unattested `opus-4-8` arm, fetch [Opus 4.8 guide, "Controlling subagent
+  spawning"](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-4-8#controlling-subagent-spawning)
+  live. As of: 2026-11-03. Recheck trigger: the Opus 5 section stops advising caps on delegation,
+  or the Opus 4.8 section starts advising them. Pointer for the two Fable arms: on a `fable-5`
   target, fetch [Fable 5 guide, "Parallel subagents"](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5#parallel-subagents)
   live; on a `fable-5-1` target, fetch [Fable 5.1 guide, "Let the lead agent keep working while subagents run"](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1#let-the-lead-agent-keep-working-while-subagents-run)
   live. As of: 2026-11-01. Recheck trigger: either section is renamed or stops advising against