Conciseness

The body is short, but the same concept is stated three times — the intro ("A CDN serves static assets from geographically distributed servers—users download from the nearest location..."), Quick Reference bullet 1 ("CDNs serve content from edge servers closest to users"), and the Explain section ("Explain how CDNs reduce latency by serving content from geographically distributed servers."), which restates a concept Claude already knows. It is mostly efficient with removable padding, above anchor 2 but not the lean anchor 5.

Actionability

The Check ("Check if static assets are served from a CDN and if the CDN is properly configured"), Fix ("Configure a CDN to serve static assets with proper caching headers and geographic distribution"), and Code Review sections are all abstract directions with no commands, code, or concrete steps — only a named list of providers ("Cloudflare, Vercel, AWS CloudFront, Fastly") and a pointer to references/rule.md. It is above anchor 1 (it does name concrete providers and what to inspect) but sits well below the executable-code anchors.

Workflow Clarity

The Check → Fix → Explain → Code Review sections give a rough sequence, but each step is a single vague sentence with no detail on how to perform it, no measurement commands (despite the description promising DevTools/Lighthouse verification), and no validation checkpoint such as confirming cache headers after configuring. This matches anchor 2's 'rough sequence present but many gaps; steps poorly defined' rather than anchor 3's listed-steps-with-implicit-checkpoints.

Progressive Disclosure

The body acts as a short overview with a clearly signaled one-level-deep reference — "For full implementation details, code examples, and framework-specific guidance, see `references/rule.md`" — and that file exists with the promised content (Next.js config example, caching headers). It misses anchor 5 because the body duplicates rule.md's intro text and Quick Reference claims instead of cleanly splitting overview vs. detail.

Specificity

The description lists several concrete actions — "auditing slow page loads, heavy assets, or rendering delays", "Verify the actual bottleneck in DevTools, Lighthouse, or field data", "before recommending changes" — with named tools. It falls short of a 5 because "recommending changes" is generic and coverage of what the audit covers beyond verification is thin.

Completeness

Both parts are present: an explicit "Use when auditing slow page loads, heavy assets, or rendering delays..." trigger clause, and a what ("Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes"). It does not match anchor 5 because the what is garbled by the templated phrase "related to Use a content delivery network", which obscures the actual capability (CDN audit/configuration guidance).

Trigger Term Quality

Natural user phrases like "slow page loads", "heavy assets", "rendering delays", "DevTools", and "Lighthouse" are present and would be said by users with this problem. A few natural terms are missing ("CDN" itself never appears as a keyword, nor "latency", "slow site", "network waterfall"), so it does not reach anchor 5; it is clearly above the 'some relevant keywords' anchor 3.

Distinctiveness Conflict Risk

The trigger terms ("slow page loads", "heavy assets", "rendering delays") are generic performance complaints that would equally match sibling performance skills (image optimization, lazy loading, bundling), and the only CDN-specific tie is the awkwardly inserted rule title. It is more specific than anchor 2's broad overlap but does not achieve anchor 4's 'minor overlap risk with closely related skills'.