check-skill-pair

name	check-skill-pair
description	Audits pair-level integrity of a primitive-pair (the artifact `/build:build-skill-pair` produces) by walking the four required artifact slots — principles doc, `build-<primitive>/SKILL.md`, `check-<primitive>/SKILL.md`, and the `primitive-routing.md` registration — and reports cross-artifact issues a per-SKILL.md checker cannot see: missing principles doc, divergent principles paths between halves, absent routing registration, missing build→check handoff. Per-half structural compliance with the unified pattern (`check-skill-pattern.md`) is delegated to `plugins/build/_shared/scripts/check_skill_pattern.py`. Use when the user wants to "audit a skill pair", "review a primitive pair", or "validate the skill pair for X". Not for auditing a single SKILL.md — route to `/build:check-skill`. Not for re-distilling a stale principles doc — route to `/build:build-skill-pair`.
allowed-tools	Read, Write, Edit, Bash, Grep, Glob
argument-hint	[primitive-name]
references	["../../_shared/references/brief-best-practices.md","../../_shared/references/check-skill-pattern.md","../../_shared/references/primitive-routing.md","../../_shared/references/skill-locations.md","../../_shared/references/skill-pair-best-practices.md","references/check-brief-content-quality.md"]
license	MIT

Check Skill Pair

Audit a primitive-pair for cross-artifact integrity. Per-SKILL.md concerns (description quality, frontmatter shape, body length) are covered by /build:check-skill. Per-half structural pattern compliance is covered by plugins/build/_shared/scripts/check_skill_pattern.py. This skill catches the issues that only surface when you look at the four required artifacts together.

This skill follows the check-skill pattern. Tier-1 + Tier-3 detection is in scripts/audit_pair.py (10 rule_ids; emits a JSON array of envelopes via _common.py). Tier-2 has one judgment dimension at references/check-brief-content-quality.md (read inline by the primary agent during evaluation).

<SKILL_ROOT> and <SHARED_REF_DIR> resolve from the chosen target — see skill-locations.md for the prefix table.

When to use

Also fires when the user phrases the request as:

• "check pair integrity"
• "is this pair consistent"

Workflow

1. Scope

Parse $ARGUMENTS as the primitive name (kebab-case, no path prefix). Refuse on empty input — this skill operates on a named primitive, not a configuration. Confirm scope aloud in one line: Auditing skill-pair for primitive: <name>.

The four required artifact slots audit_pair.py inspects:

• Principles doc: <SHARED_REF_DIR>/<name>-best-practices.md
• Build skill: <SKILL_ROOT>/build-<name>/SKILL.md
• Check skill: <SKILL_ROOT>/check-<name>/SKILL.md
• Routing registration: <SHARED_REF_DIR>/primitive-routing.md (both route lines; required for plugin target, optional otherwise)

Plus the optional brief: .briefs/<name>.brief.md (warn-level; content quality judged in Tier-2).

2. Target

Pick the placement scope before invoking the script. If $ARGUMENTS includes --target <plugin|project|user>, use it. Otherwise apply the inference rule from skill-locations.md: walk up CWD for a plugin source tree, then for a project .claude/ directory, falling back to user. Surface the inferred target in one line and confirm before invoking the script.

3. Tier-1 + Tier-3 Deterministic Checks

Execute the deterministic audit, passing the resolved target:

python3 plugins/build/skills/check-skill-pair/scripts/audit_pair.py \
  --target <plugin|project|user> <name>

The script emits a JSON array of 10 envelopes to stdout. Each envelope:

{
  "rule_id": "<rule>",
  "overall_status": "pass" | "warn" | "fail" | "inapplicable",
  "findings": [
    {
      "status": "warn" | "fail",
      "location": {"line": int, "context": str} | null,
      "reasoning": "<≤2 sentences>",
      "recommended_changes": "<canonical repair recipe>"
    }
  ]
}

recommended_changes is canonical — copy it through to the report; do not paraphrase.

Rule set (10 rules):

Tier	rule_id	Severity
1	principles-doc-presence	fail
1	build-skill-presence	fail
1	check-skill-presence	fail
1	check-rule-files-presence	fail
1	routing-registration-presence	fail (plugin target) / warn (project, user)
1	brief-presence	warn
2	principles-doc-structure	warn
3	shared-principles-path	fail
3	check-half-references-principles-doc	warn
3	build-to-check-handoff	warn

Exit codes: 0 if no envelope is fail; 1 if any envelope is fail; 64 on argument error.

No-pair-found behavior. When principles_doc + both SKILLs are all missing, the 3 presence rules emit fail envelopes; the other 7 envelopes emit overall_status: inapplicable (the audit cannot read what doesn't exist). Surface this case explicitly: "No pair found for <name> — recommend /build:build-skill-pair <name>". There is nothing else to audit.

4. Tier-2 — Brief content quality (judgment)

If brief-presence's envelope is pass (or warn only for sections missing — the brief itself exists), evaluate it against references/check-brief-content-quality.md.

Skip this Tier when the brief is absent entirely — Tier-1 already flagged it and there is nothing to read.

Evaluator policy

• Single locked-rubric pass. Read check-brief-content-quality.md first, then evaluate the brief's prose against the unified rubric. A single locked-rubric pass produces stable scoring.
• Default-closed when borderline. When evidence is ambiguous, return warn, not pass.
• Severity floor: WARN. Brief content quality is coaching, not blocking — the build still works; the trace just leaks intent.
• One finding maximum. If both So-what and Scope boundaries fail, surface the higher-signal one with concrete excerpts.

5. Report

Merge the Tier-1/3 JSON envelopes and the Tier-2 judgment finding (if any) into a unified findings table:

| Tier | rule_id | Artifact | Status | Reasoning |
|------|---------|----------|--------|-----------|

Sort: fail before warn before inapplicable; within severity, Tier-1 before Tier-2 before Tier-3. Summary line at top and bottom: N fail, N warn, N inapplicable across 4 artifact slots. If any envelope is fail and excludes downstream tiers (the no-pair case), name the trigger.

For each finding's Recommendation: line, copy the recommended_changes field through verbatim. Multi-paragraph recipes condense to the first paragraph in the report; full recipe in the opt-in repair loop.

6. Opt-In Repair Loop

Ask exactly once:

"Apply fixes? Enter y (all), n (skip), or comma-separated numbers."

For each selected finding, route per the recipe in recommended_changes:

• Direct edit — routing-doc registration (write missing route lines), check half's principles-doc reference (add to references:), build→check handoff wording. Show the diff; write on confirmation.
• Routed to another skill — missing principles doc or large-scale pair damage → recommend /build:build-skill-pair <name> to rebuild from input material; missing brief → ask whether to author a retroactive brief inline or route to the meta-skill.
• Tier-2 brief content quality — ask the user to name the specific gap / user / problem (for So-what), or list concrete in/out items (for Scope boundaries). Rewrite the section; show the diff; write on confirmation.

After each applied fix, re-run audit_pair.py (or re-judge Tier-2) on the affected scope so subsequent findings reflect the new state. Terminate the loop when the user selects no further findings, enters n, or confirms done.

Anti-Pattern Guards

1. Auditing a single SKILL.md. The pair is the unit of work here. Per-SKILL.md concerns — description routing quality, frontmatter shape, body length, ALL-CAPS density — belong to /build:check-skill.
2. Re-implementing structural pattern compliance. check-skill-pattern.md is the canonical pattern doc; check_skill_pattern.py is the canonical structural auditor. This skill audits pair-level integrity (cross-half drift, pair registration, principles-doc presence), not per-half pattern compliance. If you find yourself wanting to add "is this check half pattern-compliant" rules here, run check_skill_pattern.py against each half instead — duplication for compliance is the wrong tradeoff.
3. Bulk-applying fixes. Per-finding confirmation is required. Pair-integrity findings are often intentional mid-refactor states (a dimension in flight, a principles doc being rewritten), and bulk-applying "fixes" overwrites deliberate work.
4. Auditing principles-doc prose quality. This skill checks structural integrity — required H2 sections present, halves reference the same path — not pattern-level critique. Quality concerns about the distilled rubric are a /build:build-skill-pair re-run, not an audit task.
5. Skipping Tier-1 when Tier-2 looks juicy. Missing artifacts are the load-bearing finding. Tier-2 brief content quality reads nothing if the brief is absent — running it produces cascading misses.
6. Re-evaluating Tier-1 rules in Tier-2. Scripts are authoritative for the 10 rules they cover; trust a pass envelope.
7. Suppressing the inapplicable envelope. When no pair is found, the 7 dependent envelopes emit inapplicable — that is the user's signal that the audit couldn't read what doesn't exist. Surfacing it is the contract; hiding it silently under-audits.
8. Embellishing scripts' recommended_changes. Each rule's recipe constant is canonical guidance sourced from skill-pair-best-practices.md. Copy it through; do not paraphrase or expand.

Key Instructions

• Won't audit a single SKILL.md — the pair is the unit. Route to /build:check-skill for per-SKILL.md quality. Route to plugins/build/_shared/scripts/check_skill_pattern.py for per-half structural pattern compliance.
• Won't apply fixes without per-finding confirmation. The Repair Loop is opt-in and per-item.
• Tier-1 + Tier-3 deterministic checks are delegated to scripts/audit_pair.py — 10 rule_ids. The SKILL body only adds the check-brief-content-quality judgment pass (Tier-2) on top.
• When the primitive has no artifacts at all (principles_doc + both SKILLs all missing), the 3 presence rules emit fail; the other 7 envelopes emit inapplicable. Surface this as "No pair found for <name>" and recommend /build:build-skill-pair <name>. There is nothing else to audit.
• Recovery: this skill is read-only outside the Repair Loop. Edits produced can be reverted via git diff / git checkout; the skill itself performs no destructive actions.

Handoff

Chainable to: /build:check-skill (to audit each half's per-SKILL.md quality once structural integrity is clean); /build:build-skill-pair (to rebuild when the principles doc is missing or structurally incomplete); plugins/build/_shared/scripts/check_skill_pattern.py (per-half structural pattern compliance — separate from this skill's pair-level integrity check).