Conciseness

The body repeats the same rules three times — Stage 3 'Core Principles', the 'Quick Security/Optimization Checklists', and the closing 13-bullet 'Notes' section ('Pin all version tags (never use :latest)' appears in all three) — and inlines a ~70-line .dockerignore template that duplicates assets/example.dockerignore. The Anti-Patterns section also explains concepts Claude already knows (why running as root is bad, why :latest is non-reproducible, ADD vs COPY). This matches anchor 2 ('noticeably verbose; several unnecessary explanations or padded sections'), not 3's 'some unnecessary explanation', and not 1 since there is no library-tutorial-style padding.

Actionability

Guidance is highly concrete: the 8-item 'Always Include' list, exact BAD/GOOD instruction pairs for every rule, specific research commands (context7 resolve/get-library-docs, WebSearch query patterns), docker build/run/curl commands, and script invocation examples. It falls short of anchor 5 only because no complete Dockerfile example appears in the body itself — the templates are a reference-hop away — leaving 'minor gaps' per anchor 4.

Workflow Clarity

A 7-stage workflow with per-stage objectives, an explicit validation stage (Stage 5, hadolint/Checkov via the validator skill), a bounded feedback loop (Stage 6: fix → re-validate, max 3 iterations, document suppressed warnings), and a dedicated Error Handling section. This matches the score-5 anchor ('explicit validation steps; feedback loops for error recovery') exactly.

Progressive Disclosure

References are one level deep and clearly signaled with per-topic pointers ('Security: references/security_best_practices.md', etc.), and the scripts section explains its optional role. However, none of the six files in assets/ (e.g., nextjs-production.Dockerfile, python-fastapi.Dockerfile) are mentioned anywhere in the body, making them undiscoverable, and the inline .dockerignore template duplicates an asset — 'minor organization gaps' per anchor 4 rather than 5's 'easy navigation'.

Specificity

Enumerates multiple concrete capabilities — 'multi-stage builds, layer caching, security hardening (non-root users, minimal base images), health checks, and automatic .dockerignore creation' plus 'Validates output using devops-skills:dockerfile-validator with iterative error fixing' — in third person. Coverage is comprehensive with no notable gaps, matching the score-5 anchor rather than 4's 'minor gaps in coverage'.

Completeness

Explicitly answers both questions: a clear 'what' (generates production-ready Dockerfiles with the listed features and validates output) and an explicit 'when' via a 'Use when...' clause with concrete trigger phrases. This is the score-5 anchor structure verbatim; score 4's 'when could be more explicit' does not apply since multiple explicit triggers are given.

Trigger Term Quality

Covers natural synonyms and phrasings users would actually say: 'create, generate, write, or build a Dockerfile or docker image', 'containerize an app', 'set up a container', language names (Node.js, Python, Go, Java), and quoted phrases like 'containerize my app', 'docker-compose setup', and 'optimize my Docker build'. This matches the score-5 anchor's comprehensive synonym coverage; score 4 ('a few natural terms missing') understates it.

Distinctiveness Conflict Risk

The Dockerfile-generation niche is distinct, but the trigger 'docker-compose setup' describes a different artifact (a compose file, not a Dockerfile) and risks firing for compose-configuration requests, and validation-adjacent phrasing overlaps devops-skills:dockerfile-validator. This matches anchor 4 ('mostly distinct; minor overlap risk with closely related skills') better than 5's 'minimal conflict risk'.