Conciseness

The body is dense with non-obvious platform facts Claude cannot know ("Static assets are fresh for up to a year", "basic-auth on ANY page disables caching for the ENTIRE site", "100 lookups, 20 insertions/deletions") with essentially no padding. Minor deductions: inline version pins ("Netlify CLI 20.0.3+", "Next Runtime 5.5.0+") are time-sensitive and not in a deprecated/old-patterns section, and leaked build metadata ("<!-- Gaps: ... -->", "<!-- system: agent-context/caching/system.md ... merged by ctx-gen ...>", and the "These are org conventions, not docs facts" preamble) is token noise for the skill's consumer.

Actionability

Nearly every section gives copy-paste-ready, complete examples: full TypeScript function snippets for header caching and the Cache API, three purgeCache variants, a complete curl command with headers and JSON body, and executable cacheHeaders/fetchWithCache/needsRevalidation usage. Common cases (opt in via header, purge by tag, cache an expensive fetch, debug via Cache-Status) are each covered with specific code; score 4 would require notable gaps like pseudocode or missing key details, which are absent.

Workflow Clarity

Organization leads the reader well: "Cache-control header to reach for", "Footguns (read first)", directive reference, then task-specific sections, with a Cache-Status debugging section acting as an explicit verification path ("Check it on a deployed URL") and warnings like "an empty cache_tags list purges NOTHING" guarding risky purge operations. It falls short of 5 because there is no explicit validate-and-recover loop (e.g., verify the purge took effect, or confirm headers before/after) and purge — a semi-destructive site-wide operation — has no post-action verification step.

Progressive Disclosure

The ~330-line body has no bundle files at all (no references/, scripts/, or assets/ exist), so all content is inlined in SKILL.md. Sections are well-labeled, but the @netlify/cache helper API reference (cacheHeaders/fetchWithCache/getCacheStatus/needsRevalidation sub-sections) and the direct purge-API details are API-reference material living inline — matching the score-3 anchor of "200 lines of API reference that could be in a separate file". Score 4 would require the bulk detail to be moved out with clear in-body pointers.

Specificity

Quotes like "vary a cache key by query/header/cookie/country/language", "purge or invalidate the cache by site or cache tag", and "use the programmatic Cache API (caches.open/match/put) or @netlify/cache helpers" list multiple concrete, comprehensive actions. This sits at the score-5 anchor but the trigger clause uses second person ("Use when you add caching..."), and the rubric's voice rule penalizes second-person phrasing on this dimension by 1.

Completeness

Explicitly answers both: what — "Cache dynamic and static responses on Netlify's CDN from Functions, Edge Functions, and proxies"; when — a long "Use when you add caching or cache-control headers to a function response, tune cache TTL... or debug why a response is or isn't cached" clause with concrete trigger phrases. This is the score-5 anchor exactly; score 4 would require a less explicit 'when', which does not apply.

Trigger Term Quality

Comprehensive natural-term coverage with synonyms and API-specific vocabulary: "caching", "cache-control headers", "cache TTL", "stale-while-revalidate", "purge or invalidate the cache", "cache tag", "speed up an expensive API call", "add ISR or on-demand revalidation", and "debug why a response is or isn't cached via the Cache-Status header". Matches the score-5 anchor (analogous to "PDF files, PDFs, forms, document extraction, .pdf"); nothing common is missing.

Distinctiveness Conflict Risk

A clear niche (Netlify CDN caching) with distinct triggers (Netlify-CDN-Cache-Control, durable cache, purgeCache, @netlify/cache, Cache-Status). Only trivial overlap risk with a generic web-caching skill; not the score-4 anchor because the trigger phrases are platform-specific enough to avoid firing for non-Netlify work.