Conciseness

Nearly every passage carries non-obvious, failure-mode-specific guidance — grep routing patterns, the sibling-verb comparison procedure, JWT options tabulation, __Host- prefix fallback — with no filler explaining concepts Claude already knows. It falls short of anchor 5 because the four-heading shape rule is restated at least five times (Step 0 twice, the Step 2 mid-run check, Report shape, and the final check), and several rules carry multi-sentence justifications that could be trimmed without losing the instruction.

Actionability

Guidance is fully executable throughout: exact bash for merge-base resolution, a copy-paste heredoc report skeleton, a grep routing table with concrete patterns, per-finding shape-check commands with expected output ('It must print 4'), the exported-function grep for sibling-verb grouping, and an exact finding-format template. This matches anchor 5's copy-paste-ready commands covering the common cases.

Workflow Clarity

A clearly sequenced pipeline — skeleton first, route the diff, work mandatory sections, then final shape check — with explicit validation checkpoints and feedback loops: the mid-run 'grep -c' heading count 'as soon as the first finding is in the file', recovery instructions when it prints the wrong number, and a repeat check on the finished file. This matches anchor 5's explicit validation, error-recovery, and checklist pattern.

Progressive Disclosure

Structure matches anchor 5: the main file holds the workflow plus the checklists this repo's evals actually exercise, while the nine less-exercised sections are in the real, one-level-deep references/checklists.md (verified: all nine named sections exist there) and compliance detail in references/compliance.md, each explicitly signaled with when to open it ('open the file whenever Step 1 routes to one of them'). The split rationale is stated, and the nine section names are listed inline so navigation requires no guessing.

Specificity

The description names concrete actions — "reviewing a branch diff for security concerns" and "reporting findings with S-C/H/M/L IDs in the four-field format" — plus an enumerated concern list ("auth, tokens and sessions, injection, secrets, cookies, CSP and third-party content"). It stops short of anchor 5 because the skill's substantial compliance-review scope (GDPR/CCPA/DSA/EAA findings with C- IDs) is absent, leaving a minor coverage gap rather than the comprehensive coverage anchor 5 requires.

Completeness

Both halves are explicit: what — review a branch diff for named security concern classes and report findings in a defined ID/format scheme; when — "Use when reviewing a branch diff for security concerns". This matches anchor 5's 'clearly and explicitly answers both what AND when with concrete trigger phrases', mirroring the good example's structure.

Trigger Term Quality

Strong natural vocabulary — "security", "review", "branch diff", "auth", "tokens", "sessions", "injection", "secrets", "cookies" — that a user asking for a security pass on a branch would readily produce. A few common synonyms are missing ("vulnerability", "OWASP", "secure code review", "privacy/compliance"), which fits anchor 4's 'good keyword coverage; a few natural terms missing' rather than anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

The security focus, specific concern list, and S-C/H/M/L ID scheme give it a clear niche, but "reviewing a branch diff" is phrasing a user would also say for a general code review or quality pass, creating minor overlap risk with closely related review skills — anchor 4 rather than anchor 5's 'minimal conflict risk'.