skill-stocktake

name	skill-stocktake
description	Audit installed Claude skills for quality and surface Keep/Improve/Update/Retire/Merge verdicts. Use when the user says "audit my skills", "stocktake", "review my skills", "which skills should I retire or merge", "do a quality pass over my skills", or "/skill-stocktake". NOT for creating or improving a single skill (that is skill-creator) and NOT for whole-config GC across hooks/permissions/MCP (that is config-gc).
license	MIT
metadata	{"author":"shimo4228","version":"3.0","extracted":"2026-02-21"}
origin	shimo4228

skill-stocktake — Skill Quality Audit

Evaluate installed skills and assign each a verdict: Keep / Improve / Update / Retire / Merge. This skill does NOT do the improving — once it has a verdict, it hands off to skill-creator (the improvement engine). That boundary is the point: stocktake is the quality gate, skill-creator is the fixer.

Design note (v3.0). v1 batched ~20 skills per subagent with no cross-batch view — overlap was structurally invisible. v2.0 swung to everything-in-one-context on the 1M-context premise. A 2026-07-13 controlled comparison falsified half of that premise: the single-context pass had returned 84/84 Keep, while fresh-context batches with unconditional reference verification surfaced 12/73 non-Keep (half with deterministic evidence — 404 links, deleted files, retired CLI flags), and a dedicated overlap probe reproduced the set-level dimension without needing all bodies in one context (0 genuine duplications across 17 clusters, all documented layering). Two mechanisms explained the gap: (1) per-item attention dilutes as the context fills, and (2) a conditional verification trigger ("confirm if it looks stale") degrades to "never verify" in a loaded context, because the trigger itself is a diluting judgment. v3.0 is therefore a hybrid, split not by context length but by the property being checked (see when-code-when-llm): deterministic checks are code-owned and unconditional; per-item judgment gets narrow, dense contexts; set-level judgment gets a light description sweep with targeted deep reads.

Modes ($ARGUMENTS)

Argument	Behavior
none / full	Evaluate every skill (default)
changed	Re-evaluate only skills whose SKILL.md mtime is newer than results.json's evaluated_at; carry the rest forward from the ledger. Phase 0 and Phase 3 still run over the full set (structural debt and overlap are set properties)

changed detects changes inline (no script):

find ~/.claude/skills -name SKILL.md -newermt "$(jq -r .evaluated_at ~/.claude/skills/skill-stocktake/results.json)"

Phase 0 — Structural pre-pass (deterministic, code-owned)

Run BEFORE any LLM judgment. These checks never ride on per-item attention:

1. skill-health scan — dangling references / missing artifacts across the library (run its scanner per ~/.claude/skills/skill-health/SKILL.md). Mandatory, not optional: this is the structural layer of Curate (ADR-0019 layering), and the v2.2 verification showed exactly these defects slipping through judgment-owned checks.
2. Ledger hygiene — for every results.json entry: the path must exist on disk and the key must follow the canonical rule below. Dedup violations (same path under two keys → keep learned/<name>, delete the bare key). Entries whose path no longer exists are removed (note them in the report as retired-from-disk).
3. Existence before judgment — a skill that fails the existence check never reaches Phase 2. Do not let an LLM assign Keep to a file that is not there (this happened: two nonexistent paths carried Keep verdicts in the 2026-07-05 ledger).

Phase 1 — Inventory

Enumerate skill definition files with Glob (no script needed):

• ~/.claude/skills/*/SKILL.md
• ~/.claude/skills/learned/*.md
• if cwd has .claude/skills/, also {cwd}/.claude/skills/*/SKILL.md (project skills)

Canonical ledger keys: a skill under learned/ is keyed learned/<name> in results.json — never bare <name>. A rule or skill referencing a learned note by bare name does NOT make it a top-level skill.

Usage counts (parent-owned; batch agents never see them): read ~/.claude/metrics/skill-usage.jsonl inline (the hook log-skill-usage.sh appends to it) and count per-skill events over 7 / 30 / 90 days. Aggregate with a throwaway python3/jq one-liner.

• If the log is missing or its first event is younger than 90 days, render usage as — (unmeasured). Never render it as 0 — unmeasured and unused are different facts.
• slash events exist only from 2026-07-03. For windows straddling that date, treat counts for user-invocable skills as lower bounds, and never Retire on low usage alone when the skill's primary mode is user-typed slash invocation.

State the scan result up front: which paths were scanned, how many skills found, and whether usage is measurable.

Phase 2 — Per-item scrutiny (parallel small batches, fresh contexts)

Split the target set into batches of 10–12 files, interleaving learned/ notes across batches, and launch one subagent per batch in parallel. Small batches are the point: per-item attention dilutes as a context fills, and the 84/84-Keep failure mode is exactly that dilution. Do NOT pass prior verdicts or the ledger to batch agents (anchoring); do NOT pass usage data (parent-owned dimension).

Each batch agent applies, per skill:

Stage 1 — binary screen. Explicit Yes/No per item; surface only the No answers:

• Actionability: concrete steps/commands/examples you can act on?
• Scope fit: name, trigger (description), and body aligned — not too broad or narrow?
• Within-batch uniqueness: no content overlap with other skills in this batch? (a documented orchestrator/sub-skill split is NOT overlap; cross-batch overlap is Phase 3's job, not this agent's)
• Currency: unconditionally verify every artifact the skill names — ls each referenced path (~/.claude/agents/<name>.md, hooks, bundled scripts), run --help / version checks for named CLI flags, fetch named URLs. "Verify if it looks stale" is banned phrasing: the condition is what dilutes. Deterministically checkable claims get deterministic checks, every time.

Stage 2 — verdict pressure-test (non-Keep candidates only). Generate 1–3 skill-specific atomic yes/no questions that try to refute the draft verdict before finalizing it. Answer each with one line of evidence (file read, path check, WebSearch). A refuted defect → fall back toward Keep. A confirmed defect → the No answers become the concrete improvement list handed to skill-creator (Improve/Update) or the removal rationale (Retire).

Evaluation is holistic judgment, not a numeric rubric — binary answers are evidence feeding the verdict, never aggregated into a score (a satisfaction ratio changes no decision and dilutes a single dominant No). Batch agents return structured verdicts with self-contained reasons; Keep-bound skills get no dynamic questions.

Phase 3 — Overlap probe (one dedicated agent, set-level)

Cross-skill duplication is a set property; it gets a specialist, not a side effect. One agent, whole library:

1. Read name + description (+ heading structure) of every target file — light pass.
2. Propose candidate overlap clusters greedily (false positives are fine at this stage).
3. For each candidate cluster, read the bodies side by side and judge:
   • GENUINE_DUPLICATION — removing one loses nothing; name the Merge target
   • DOCUMENTED_LAYERING — orchestrator→sub-skill, rule→skill, declared defer; quote the defer line as evidence
   • ADJACENT_BUT_DISTINCT — near domain, different job
4. One extra pass over ~/.claude/rules/ and MEMORY.md: is a rule re-stating a skill (or vice versa) beyond a declared pointer? Flag promotion residue (a learned note whose content a rule has fully absorbed) as Retire/Merge candidates.

Only GENUINE_DUPLICATION produces Merge verdicts. This probe is what replaces the v2.0 "everything in one context" rationale — it recovers the set-level view at description granularity plus targeted deep reads, without diluting Phase 2.

Phase 4 — Synthesis (parent)

Merge Phase 2 verdicts, Phase 3 overlap verdicts, and parent-owned usage data:

• Zero-usage rule: when the usage log's first event is at least 90 days old AND a skill has use_90d == 0, surface it as a Retire candidate (final call is the user's). While the log is younger than 90 days this rule does not fire.
• Aggregate cost (set-level): holding a skill is not free even when it is individually fine. Skill benefits are fragile — a large, uncurated library degrades skill selection and pulls behaviour back toward the no-skill baseline. The Keep bar rises with library size: when the set is large, a merely-adequate skill (rare use, low uniqueness, heavy adjacency) is a Retire/Merge candidate on aggregate-dilution grounds alone. A judgment input, never a quota.
• Conflicts (e.g. batch says Keep, probe says Merge) are resolved by the parent reading the cited evidence, not by vote.

Verdict	Meaning
Keep	Useful, current, unique value
Improve	Worth keeping, but specific improvements needed
Update	Referenced technology/artifact is outdated (verified, with evidence)
Retire	Low quality, stale, or cost-asymmetric
Merge into [X]	Genuine duplication confirmed by the overlap probe; name the target

Evaluation is origin-blind: the same checklist applies to every skill.

Render a table: Skill | 7d | 90d | Verdict | Reason.

Phase 5 — Consolidation

Confirm one by one (config-gc's confirm-each design): walk the non-Keep candidates sequentially — for each, show the evidence first, then ask [y/n/skip]. Never batch the approval. The user can stop at any point; skip records the verdict in the ledger unactioned.

• Retire / Merge: per file, present (1) the specific defect found, (2) what covers the same need instead, (3) the impact of removal (dependent skills, rule pointers, MEMORY references) → ask [y/n/skip]. Act only after the user confirms that file.
• Improve / Update: offer per skill — "Hand <skill> to skill-creator? [y/n/skip]" — and on approval invoke skill-creator with the target skill and the No-answer list. Stocktake never does the improvement work itself.
• Update the ledger: Read results.json → merge this run's verdicts → Write it back (evaluated_at = real UTC from date -u +%Y-%m-%dT%H:%M:%SZ). In changed mode, preserve the prior verdicts of skills you did not re-evaluate.
• If MEMORY.md exceeds 100 lines, propose compression.

Reason quality (required)

Every reason must be self-contained — decision-enabling on its own. "unchanged" alone is banned; always restate the evidence. For non-Keep verdicts, the reason cites the No answers from the binary screen / pressure-test (question + one-line evidence).

• Retire: state the defect + the replacement. Bad: "Superseded" / Good: "disable-model-invocation: true already set; continuous-learning-v2 covers the same patterns plus confidence scoring. No unique content remains."
• Merge: name the target + what to integrate. Bad: "Overlaps with X" / Good: "42-line thin content; Step 4 of chatlog-to-article already covers this workflow. Integrate the 'article angle' tip there as a note."
• Improve: which section, what change. Bad: "Too long" / Good: "276 lines; 'Framework Comparison' (L80–140) duplicates ai-era-architecture-principles. Delete it to reach ~150 lines."
• Keep (mtime-only change in changed mode): restate the original rationale.

results.json (lean ledger)

{
  "evaluated_at": "2026-06-24T11:09:00Z",
  "skills": {
    "<skill-name>": {
      "path": "~/.claude/skills/<name>/SKILL.md",
      "verdict": "Keep",
      "reason": "...",
      "mtime": "2026-01-15T08:30:00Z"
    }
  }
}

A ledger for verdict history and the last-audit timestamp only. Update it inline with Read/Write, not a script. Global skills only (project skills are read fresh from cwd, not cached here). Phase 0's hygiene rules (canonical keys, existing paths) are part of every write.

Related

• skill-creator — the improvement engine; hand off Improve/Update work to it.
• skill-health — the deterministic structural layer; Phase 0 runs its scanner as a mandatory pre-pass (enumerate-then-decide: code enumerates debt, judgment decides).
• config-gc — GC over skill existence and the whole of ~/.claude; stocktake judges skill quality.
• rules-stocktake — the same audit for ~/.claude/rules/ (residency cost instead of usage).
• repo-asset-stocktake — the same stocktake pattern for a project repo's non-code assets.
• when-code-when-llm — the dividing line Phase 0/2/3 implement: deterministic checks are code-owned and unconditional; judgment is holistic and narrow-context.
• harness-sync — use it to sync this skill to its public repo.
• Usage measurement: ~/.claude/hooks/log-skill-usage.sh → ~/.claude/metrics/skill-usage.jsonl (a measurement layer independent of stocktake).

References

The two-stage binary-question design (screen → verdict pressure-test, holistic verdict, no score aggregation) follows the checklist-decomposition evaluation line: BinEval "Ask, Don't Judge" (arXiv:2606.27226), CheckEval (arXiv:2403.18771), TICK (arXiv:2410.03608). Scores are deliberately not adopted: BinEval's own limitations show over-decomposition degrades correlation on holistic quality dimensions, and a satisfaction ratio would dilute a single dominant No.

The v3.0 hybrid architecture (deterministic pre-pass → fresh-context batches with unconditional verification → dedicated overlap probe) is grounded in a 2026-07-13 controlled comparison on this library (n=73): the v2.0 single-context pass returned 84/84 Keep while fresh-context batches surfaced 12/73 non-Keep (6 with deterministic evidence) and a dedicated probe confirmed 0 genuine duplications — i.e. per-item scrutiny dilutes in a loaded context, set-level judgment does not need one.