Conciseness

The ~145-line body is lean and assumes Claude's competence: it never explains concepts Claude already knows, and every section carries project-specific rules (slug format, question cap, status values, severity classes). It matches the level-5 anchor ('every token earns its place'); the small overlap between the intro and the closing directory-layout summary is a quick-reference aid, not padding that would drop it to level 4.

Actionability

Guidance is fully executable for an instruction-only skill: exact paths ('features/<slug>/plan.md', 'handoffs/YYYY-MM-DDTHHMM.md'), concrete slug rules ('lowercase, hyphen-separated, max 40 chars'), explicit status transitions ('Planning' → 'In Progress' → 'Complete'), and named templates for every document. Per the rubric's scoring note, absence of code is not penalized when guidance is this specific, so it fits level 5 rather than level 4's 'minor gaps'.

Workflow Clarity

Phases 0–5 are clearly sequenced with explicit validation checkpoints and feedback loops: the Phase 0 requirements gate ('Do NOT proceed until you have clear answers'), the Phase 2 approval gate ('Wait for explicit approval... before writing any code'), the Phase 3 deviation loop ('stop, update plan.md, and tell the user'), and Phase 5's review with severity classes and 'Fix all 🔴 items before proceeding'. This matches the level-5 anchor including checklists and error-recovery loops.

Progressive Disclosure

The body is a lean overview that pushes all template bulk into a single real, one-level-deep reference, clearly signaled ('See [references/templates.md](references/templates.md)') and referenced by template name at each phase; the bundle confirms all referenced templates (Features Index, Feature README, Plan, Changes, Review) exist in that file. This matches the level-5 anchor for well-signaled one-level-deep references with easy navigation.

Specificity

The description lists multiple concrete actions — 'Creates a features/<slug>/ directory containing a living spec (README.md), technical plan (plan.md), implementation log (changes.md), and review report (review.md)' and enumerates phases ('requirements clarification, codebase pattern survey, plan approval gate, implementation, UML.md update, and diff review') — giving comprehensive, specific coverage in third-person voice. It clearly matches the level-5 anchor rather than level 4, which expects minor gaps in coverage.

Completeness

It explicitly answers both 'what' (structured workflow producing named artifacts in features/<slug>/) and 'when' ('Use whenever a user asks to add, build, or implement a new feature, integration, job, endpoint, or module') with concrete trigger phrases. This matches the level-5 anchor exactly; level 4 would require the 'when' to be less explicit.

Trigger Term Quality

'Use whenever a user asks to add, build, or implement a new feature, integration, job, endpoint, or module' provides good synonym and object-type coverage. A few natural phrasings users might say ('create', 'set up', 'write me') are absent, so it sits at the level-4 anchor ('good keyword coverage; a few natural terms missing') rather than the comprehensive level-5 example.

Distinctiveness Conflict Risk

The feature-addition workflow with its specific artifacts (features/<slug>/, plan.md, UML.md, handoffs/) is a mostly distinct niche, but 'whenever a user asks to... build... endpoint, or module' is broad enough to overlap with general implementation or review skills. Minor overlap risk fits the level-4 anchor; the level-5 anchor demands minimal conflict risk with distinct triggers.