Conciseness

The body is essentially a functional index: 70 rule names each with a one-line actionable summary (e.g., 'Use Promise.all() for independent operations', 'Use next/dynamic for heavy components'), with no padding or explanation of concepts Claude already knows. It matches anchor 4 ('Efficient; minor instances... that could be trimmed'): the priority/impact information is duplicated between the 8-row priority table and the section headers ('### 1. Eliminating Waterfalls (CRITICAL)'), and 'When to Apply' partially restates the frontmatter description. Not a 5 because of that duplication; not a 3 because nearly every line is a usable lookup entry, not verbosity.

Actionability

Each rule entry gives a concrete, API-level directive (e.g., 'Use React.cache() for per-request deduplication', 'Use LRU cache for cross-request caching', 'Use content-visibility for long lists', 'Use toSorted() for immutability'), and 'How to Use' gives explicit file paths to open for full code examples. This matches anchor 4 ('Mostly executable guidance; concrete code or commands with minor gaps'). Not a 5 because the body contains no code examples or commands itself — all executable detail is delegated to rule files; not a 3 because the one-liners are specific, actionable heuristics rather than vague direction.

Workflow Clarity

The usage flow is clear and unambiguous for a reference skill: 'When to Apply' scopes the task, the priority table tells the model which category matters most, rule prefixes make file lookup deterministic, and 'Read individual rule files for detailed explanations and code examples' states the action. This matches anchor 4 ('Clear sequence with most checkpoints present; minor validation gaps'). Not a 5 because 'How to Use' only lists two example paths rather than an explicit step sequence (identify task -> pick category by priority -> open rules/<prefix>.md), and there is no guidance on what to do when multiple rules conflict; not a 3 because this is a non-destructive lookup skill where the single action (consult index, open rule file) is unambiguous.

Progressive Disclosure

The design intent is right — a concise overview with one-level-deep, clearly signaled references ('Read individual rule files... rules/async-parallel.md', 'For the complete guide with all rules expanded: AGENTS.md'). However, scored against the actual bundle structure, none of the referenced files exist: there is no rules/ directory, no AGENTS.md, and no references/, scripts/, or assets/ directories at all. Every piece of detailed content is delegated to files that are not shipped, so navigation dead-ends. This matches anchor 3 ('Some structure but could be better organized; references present but not clearly signaled') in effect: the structure is present but the reference layer is broken. Not a 4/5 because well-signaled references only count when the referenced files are actually present in the bundle; not a 2 because the SKILL.md itself is well organized with clear sections and a consistent prefix-based naming convention.

Specificity

Quotes: 'React and Next.js performance optimization guidelines from Vercel Engineering', 'writing, reviewing, or refactoring React/Next.js code', 'data fetching, bundle optimization, or performance improvements'. It names the domain plus several concrete application areas (writing, reviewing, refactoring, data fetching, bundle optimization), matching anchor 4 ('Lists several specific actions; minor gaps in coverage'). Not a 5 because it never states the concrete capabilities the skill provides (e.g., eliminating waterfalls, re-render optimization, bundle analysis rules); not a 3 because more than 1-2 concrete actions are named.

Completeness

Quotes: what — 'React and Next.js performance optimization guidelines from Vercel Engineering'; when — 'This skill should be used when writing, reviewing, or refactoring React/Next.js code... Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.' Both what and when are explicitly and concretely answered with trigger phrases, matching anchor 5 exactly. A 4 would require the 'when' to be less explicit; here it is fully specified.

Trigger Term Quality

Quotes: 'React components, Next.js pages, data fetching, bundle optimization, or performance improvements', 'writing, reviewing, or refactoring React/Next.js code'. These are natural phrases users would say, matching anchor 4 ('Good keyword coverage; a few natural terms missing'). Not a 5 because common variations like 'bundle size', 'optimize renders', 're-renders', 'slow app', or 'hydration' are absent; not a 3 because coverage goes well beyond a couple of generic keywords and includes the most likely trigger phrasing.

Distinctiveness Conflict Risk

Quotes: 'React and Next.js performance optimization guidelines', 'Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization'. This is a clear niche (Vercel-maintained React/Next.js performance rules) with distinct, domain-specific triggers and minimal conflict risk with unrelated skills, matching anchor 5. Not a 4 because the scope is tightly bounded to React/Next.js performance rather than overlapping broadly with general web or code-review skills.