Conciseness

The code and anti-patterns earn their place, but there is structural repetition: "When to Activate" and "When to Use" list nearly identical bullets (file processing pipelines, --cache/--no-cache CLI, caching pure functions), and the "Key Design Decisions" table plus "Best Practices" restate rationale already given inline ("Path-independent, auto-invalidates on content change", "Handle corruption gracefully", "Keep processing functions pure"). Not 2 because nothing explains concepts Claude already knows and the code sections are tight; not 4 because two whole sections plus a table are padding that could be consolidated.

Actionability

Concrete, executable Python for hashing (compute_file_hash), storage (write_cache/read_cache), and the service wrapper (extract_with_cache) with hit/miss logging and corruption handling. Not 5 because serialize_entry/deserialize_entry, extract_text, and ExtractedDocument are referenced but undefined, so the code is not fully copy-paste runnable; not 3 because those placeholders are domain-specific seams rather than pseudocode, and everything shown is real executable code.

Workflow Clarity

The pattern is clearly sequenced in four numbered subsections, and extract_with_cache shows the full check-hit/miss-extract-store flow with corruption treated as a miss and re-processed (a recovery checkpoint: "Treat corruption as cache miss"). Not 5 because there is no explicit validation of cache writes (e.g., verifying the written entry round-trips) and no stated post-write check; not 3 because the sequence is explicit and error/corruption handling is built in rather than absent.

Progressive Disclosure

No bundle files exist, and the body is well organized into clear sections (Core Pattern, Key Design Decisions, Best Practices, Anti-Patterns, When to Use / When NOT to Use) that keep the single pattern easy to navigate. Not 5 because at ~155 lines it exceeds the under-50-line simple-skill case, and the duplicated When to Activate/When to Use sections show minor organization gaps; not 3 because nothing that clearly belongs in a separate reference file is inlined and navigation is easy.

Specificity

"Cache expensive file processing results using SHA-256 content hashes — path-independent, auto-invalidating, with service layer separation" names the domain and several concrete actions (hash-keyed caching, invalidation on content change, service layer separation), with minor gaps (no mention of specific file types like PDFs/images that it handles). Not 5 because coverage of capabilities is narrower than the comprehensive multi-action anchor; not 3 because it lists several specific mechanisms rather than just 1-2 generic actions.

Completeness

Explicitly answers both: what — "Cache expensive file processing results using SHA-256 content hashes"; when — "Use when repeated file processing is slow and results should be cached and invalidated by content rather than path". This matches the anchor for a clear 'what' plus a concrete, explicit 'Use when' trigger clause.

Trigger Term Quality

Natural phrases a user would say are present: "repeated file processing is slow", "results should be cached", "invalidated by content rather than path", plus "SHA-256" and "cache". Not 5 because common synonyms like "memoize/memoization", "speed up", or specific file-format terms (PDF, image) are missing; not 3 because keyword coverage goes well beyond a single generic term.

Distinctiveness Conflict Risk

The content-hash-keyed caching niche ("path-independent, auto-invalidating", "invalidated by content rather than path") is a clear, distinct trigger surface. Not 5 because it could still be pulled in by broader performance/caching requests that aren't file-processing-specific; not 3 because the content-hash framing strongly distinguishes it from generic caching skills.