Conciseness

The body is dense with genuinely non-obvious domain knowledge (force-push detection via `payload.distinct_size = 0`, the `commits/SHA` vs `git/commits/SHA` 404 trick, CDX query patterns, rate-limit budgets) and avoids explaining concepts Claude already knows. It is not a 5 because of repeated content: role boundaries are stated once in the guardrails and again per investigator, the `evidence-store.py list` invocation appears in Phases 0, 3, and 7, and the rate-limiting and ethical-use sections could be trimmed or moved to a reference.

Actionability

Mostly executable, copy-paste-ready commands: full git forensics pipelines, concrete GitHub REST API curl calls, CDX API URLs with parameters, and BigQuery templates with mandatory dry-run cost rules. It falls short of anchor 5 because `evidence-store.py add` is invoked repeatedly ("add via `python SKILL_DIR/scripts/evidence-store.py add`") without ever showing the actual add syntax (flags for type/content/SHA), and commands use unsubstituted placeholders (OWNER/REPO, YYYYMM, NUM) rather than worked examples.

Workflow Clarity

The 8 phases are explicitly sequenced with strong validation checkpoints and feedback loops: Phase 5 mechanically verifies cited evidence IDs (hard failure on missing IDs), Phase 3 verifies `content_sha256` hashes and requires 2-source verification for `[VERIFIED]`, and rejected hypotheses feed back into Phase 4 for refinement with a max-3-iteration bound. This matches anchor 5 ("Clear sequence with explicit validation steps; feedback loops for error recovery; checklists for complex processes") — the anti-hallucination guardrails function as a checklist, and the destructive/batch cap does not apply since validation is pervasive.

Progressive Disclosure

The body itself is structured as a proper overview — each phase points to one-level-deep, clearly-signaled references ("See [evidence-types.md](./references/evidence-types.md) for IOC taxonomy") with a Reference Materials index — but scoring against the actual bundle reveals that `templates/forensic-report.md`, referenced three times and load-bearing (Phase 0 step 3 copies it; Phase 6 populates it), does not exist in the bundle, so the workflow breaks at initialization. The four references/ files and scripts/evidence-store.py do exist, but a missing referenced file is a real navigation/integrity gap beyond anchor 4's "minor organization gaps".

Specificity

"GitHub supply-chain forensics: recovery, IOCs, reporting." names the domain clearly and lists three actions, but each action is generic and unattached to an object (recovery of what — force-pushed commits? deleted PRs?), unlike anchor 4's "Extracts text from PDF files, fills forms, converts pages to images". It is above anchor 2 because it does enumerate multiple domain actions rather than minimal generic ones.

Completeness

The description gives a clear 'what' ("GitHub supply-chain forensics: recovery, IOCs, reporting") but contains no 'Use when...' clause or any equivalent trigger guidance, which per the judging guidelines caps completeness at 3. It is not a 2 because the 'what' is present and specific, not vague.

Trigger Term Quality

Terms like "GitHub", "supply-chain", "forensics", "IOCs" are relevant, but the most natural user phrasings — "compromised", "investigate this repo", "supply chain attack", "force push", "suspicious commit" — are absent, matching anchor 3 ("Some relevant keywords but missing common variations or synonyms"). It does not reach anchor 4 because the keyword set is thin (six terse terms) and misses the phrasing a user would most plausibly say.

Distinctiveness Conflict Risk

"GitHub supply-chain forensics" carves out a distinct niche with low overlap risk against unrelated skills. It falls short of anchor 5 because the trailing terms "recovery... reporting" are generic security-incident vocabulary that could collide with broader incident-response or code-review skills, leaving minor overlap risk (anchor 4: "Mostly distinct; minor overlap risk with closely related skills").