Conciseness

The body is a lean index — every rule gets a one-line summary and nothing explains concepts Claude already knows. Minor over-explanation remains: the `impact:` front-matter field is explained twice ("Each rule carries its own `impact:` value in the front matter..." and "Impact labels below are the `impact:` value from each rule file's front matter"), and the category-vs-impact justification paragraph could be trimmed slightly.

Actionability

Guidance is concrete and executable for an index document: exact rule file names with prefixes (`async-`, `bundle-`), per-rule impact labels for prioritization, and an explicit instruction to "work top-down when reviewing" and "Read individual files as needed". It stays at 4 rather than 5 because no executable steps or examples are inline — all actionable content is delegated to the reference files.

Workflow Clarity

A clear sequence is present: prioritize categories top-down by the priority table, then open the specific rule file indicated by prefix and impact. No validation checkpoints are included, but none are needed — this is an advisory/review skill with no destructive or batch operations, so the score-3 cap does not apply. It falls short of 5 because the workflow is a single ordering instruction rather than an explicit sequenced process with checkpoints.

Progressive Disclosure

Verified against the actual bundle: all 37 rule names quoted in the body exist as files in `references/`, exactly one level deep, and spot-checked files carry the promised structure (`impact:` front matter, explanation, incorrect/correct code pair, context). SKILL.md is a clean overview with well-signaled one-level references — a direct match for the score-5 anchor.

Specificity

Concrete verbs appear ("asks to review, profile, or speed up React code") alongside enumerated focus areas ("data-fetching waterfalls, bundle size, memoization (React.memo / useMemo / useCallback), caching fetched data in localStorage"). The 'what' leans topical — a list of problem areas rather than a comprehensive set of distinct actions like the score-5 anchor — so it sits at 'several specific actions with minor gaps', not clearly one anchor above.

Completeness

Explicitly answers both questions: what ("Performance optimization for React applications — rendering, re-renders, data-fetching waterfalls, bundle size, and the JavaScript hot paths inside components") and when ("Use when the user mentions slow or janky renders..."). Both are concrete and explicit with trigger phrases, exactly matching the score-5 anchor.

Trigger Term Quality

Comprehensive natural phrasing with synonyms and API names users would actually say: "slow or janky renders", "unnecessary re-renders", "lazy loading", "code splitting", "request waterfalls", "duplicate or repeated API requests", "laggy scrolling or typing", "React.memo / useMemo / useCallback". Matches the score-5 anchor (synonyms plus specific API identifiers); nothing common is missing.

Distinctiveness Conflict Risk

Clear niche (React performance optimization) with explicit boundary carve-outs: "Not a general React authoring guide — for folder and layer structure use react-feature-sliced-design, for language and typing questions use typescript-development." Distinct triggers plus explicit disambiguation from sibling skills minimize conflict risk; it clearly matches the score-5 anchor rather than the score-4 'minor overlap risk' anchor.