Conciseness

Nearly every section delivers non-obvious specifics ("Rolldown (v7+) or Rollup (v5–v6)", "caches the result under node_modules/.vite", "forces up to 6 filesystem checks via resolve.extensions") with no tutorial padding. Minor over-explanation remains — the "How It Works" section reiterates native-ESM dev serving and tree-shaking/code-splitting basics Claude already knows — placing it at anchor 4 ("efficient; minor instances of over-explanation") rather than anchor 5.

Actionability

Copy-paste-ready vite.config.ts snippets cover the common cases (proxy, manual chunks, lib mode, optimizeDeps, Docker, warmup), alongside executable commands ("vite --profile" then "p+enter", "vite build && vite preview", "tsc --noEmit in CI") and explicit BAD/GOOD contrast pairs. Fully executable and comprehensive — an anchor-5 match.

Workflow Clarity

As a patterns skill it has no single linear pipeline, but its multi-step procedures are sequenced with explicit checkpoints: profiling (profile → interact → save → load in Speedscope), deploy verification ("Always verify with vite build && vite preview before deploying"), and cache-invalidation recovery. This matches anchor 4 (clear sequence, most checkpoints present) — anchor 5 would require a full end-to-end checklist, and no destructive/batch operations apply that would cap it at 3.

Progressive Disclosure

A self-contained single file (no bundle files exist) with good structure: clear section headers, comparison tables, a Quick Reference navigation table, and a Related Skills section. It stays at anchor 4 rather than 5 because ~450 lines inline several self-contained topics (plugin authoring, SSR externals, library mode, performance deep-dives) that are natural candidates for separate reference files; it is above anchor 3 because navigation is clear and nothing is buried.

Specificity

Lists nine concrete capability areas ("config, plugins, HMR, env variables, proxy setup, SSR, library mode, dependency pre-bundling, and build optimization") with comprehensive coverage, but frames them as a topic list ("patterns including...") rather than the concrete action verbs of the anchor-5 example. It is well above anchor 3 ("1-2 concrete actions") yet does not demonstrate the action-oriented phrasing of anchor 5.

Completeness

Explicitly answers both questions: what ("Vite build tool patterns including config, plugins, HMR, env variables, proxy setup, SSR...") and when ("Activate when working with vite.config.ts, Vite plugins, or Vite-based projects") with concrete trigger phrases — a direct anchor-5 match, clearly above anchor 4's softer 'when'.

Trigger Term Quality

The trigger clause includes natural phrases users would say — "vite.config.ts", "Vite plugins", "Vite-based projects" — with a filename-level trigger. Common variations are missing (bare "Vite", ".env files", "vite build", "dev server"), so it matches anchor 4 ("good keyword coverage; a few natural terms missing") rather than anchor 5's synonym-and-extension spread.

Distinctiveness Conflict Risk

Vite is a specific niche with filename-level triggers ("vite.config.ts") and tool-specific keywords, giving minimal conflict risk except negligible overlap with closely related bundler skills. Matches anchor 5 ("clear niche with distinct triggers; minimal conflict risk").