Conciseness

The body is lean (~35 lines) with terse, directive sections ("Never return raw error objects or stack traces in API responses", "Log full error details server-side"). The only trimmable material is the opening paragraph explaining attacker CVE-lookup behavior and OWASP A09 — background Claude largely already knows — which keeps it at 'efficient; minor instances of over-explanation' rather than the fully lean anchor 5.

Actionability

The Quick Reference bullets and the Code Review section give concrete, executable directives, including specific patterns to search for — "Flag any location where error.stack, error.message (raw), or internal paths are serialised directly into a response body". It stops short of anchor 5 because no code or commands appear in the body itself (implementation details are deferred to the reference), leaving minor gaps if the reference were unavailable.

Workflow Clarity

The Check → Fix → Explain → Code Review sections give a coherent, ordered review-and-remediation flow for a single-purpose skill, and the Quick Reference anchors the key rules. It fits 'clear sequence with most checkpoints present; minor validation gaps' (4) rather than 5 because explicit verification of the fix is not stated in the body — it lives only in references/rule.md's Verification section.

Progressive Disclosure

The body is a concise overview and defers all implementation details, code examples, and framework-specific guidance via a clearly signaled, one-level-deep pointer: "see `references/rule.md`" — and references/rule.md exists in the bundle and delivers exactly what the pointer promises. This matches 'clear overview with well-signaled one-level-deep references; content appropriately split; easy navigation' with no nesting or buried references.

Specificity

The description names a concrete domain and one concrete action — "reviewing error handling middleware, API route handlers, or server responses" — but offers only a single action verb rather than several specific capabilities (e.g., flag, fix, sanitize). It fits the anchor 'names domain and 1-2 concrete actions, but not comprehensive'; a 4 would require several distinct actions listed, and a 2 would require generic or minimal action language, which is not the case given the precise review targets.

Completeness

The description is solely a trigger clause — "Use when reviewing error handling middleware, API route handlers, or server responses for security-sensitive information disclosure" — with no statement of what the skill actually does (e.g., 'Flags and helps fix stack trace exposure'). This matches the anchor 'only "when" is present without "what"' (score 2); it cannot score 3 or 4 because those anchors require a clear 'what' component, which is entirely absent here.

Trigger Term Quality

Natural phrases a developer or security reviewer would say are present: "error handling middleware", "API route handlers", "server responses", "security-sensitive information disclosure". However, the most central natural terms — "stack traces", "error messages", "leaking" — are absent, so it falls just short of comprehensive synonym coverage (5) while clearly exceeding 'some relevant keywords but missing common variations' (3).

Distinctiveness Conflict Risk

The niche is fairly distinct — combining error-handling surfaces with security-sensitive information disclosure is specific enough that it would rarely fire for an unrelated skill. There is minor overlap risk with broader security-audit or error-handling skills, so it fits 'mostly distinct; minor overlap risk' (4) rather than 'clear niche with minimal conflict risk' (5).