Conciseness

The body is lean and assumes Claude's competence: no general concepts are explained, and every sentence carries non-obvious, task-specific rules (percentage semantics, denominator handling, cluster vs. island floors, the 7-day npm age gate). It matches anchor 5 ('every token earns its place') rather than anchor 4, which reserves room for trimming — the densest passage (the percentage/denominator rules) is essential to prevent double-counting, not padding.

Actionability

Highly concrete for an instruction-only skill: exact endpoint, exact query fields, exact file paths and keys to write, branch, PR template, and labels. It falls short of anchor 5's 'copy-paste ready' bar because the actual HTTP request mechanics are unstated — no example request (e.g. curl) and no specification of how PLAUSIBLE_API_KEY is passed (e.g. Authorization header) — leaving minor gaps consistent with anchor 4.

Workflow Clarity

The Auth → Query → Heuristic → Approve → Write → PR sequence is clear and includes explicit validation checkpoints and feedback loops for a destructive change: 'Fetch all pages before rolling versions', the operator approval gate with recorded identity/date, 'If browserslist cannot resolve the new pins, bump caniuse-lite', the dispute path to the Technical Architect, and the reproducibility requirement ('Reuse of the saved evidence and approval must yield the same floors'). This matches anchor 5's 'explicit validation steps; feedback loops for error recovery'.

Progressive Disclosure

The skill is a single well-sectioned file with no bundle files; all ~60 lines of operational guidance belong inline, the one external link (Plausible Stats API) is appropriately signposted, and navigation is trivial via clear section headers. There is nothing that should be split out or nested, matching the guideline that a compact, well-organized single-file skill with no external-reference need scores 5; anchor 4 would require organization gaps or misplaced content, which are absent.

Specificity

The description lists three concrete, fully specified actions covering the entire pipeline — 'Recomputes Storybook browser support floors from Plausible /docs usage', 'writes pinned versions', and 'opens a PR' — naming the domain (Storybook), data source (Plausible /docs usage), and outputs. Score 4's anchor ('minor gaps in coverage') fits less well: the three actions span analysis, write, and delivery with no missing pipeline stages.

Completeness

Both 'what' (recompute floors, write pinned versions, open a PR) and 'when' ('Use only when a human explicitly applies this skill') are explicitly present in third-person voice. It does not reach anchor 5 because the 'when' clause is a restrictive invocation guard rather than descriptive trigger phrases naming the situations that warrant the skill (e.g. 'when browser usage data needs refreshing'); it clearly exceeds anchor 3, where 'when' is missing or only implied.

Trigger Term Quality

Good keyword coverage including natural domain terms a Storybook maintainer would say: 'Storybook', 'browser support', 'Plausible', '/docs usage', 'pinned versions', 'PR'. A few natural trigger terms are missing — e.g. 'browserslist', 'caniuse', 'supported browsers' — so it falls short of anchor 5's 'comprehensive coverage... including synonyms', but is well above anchor 3's 'missing common variations'.

Distinctiveness Conflict Risk

A clear niche with minimal conflict risk: recomputing Storybook's browser support floors from Plausible analytics is highly specific and unlikely to trigger for any other skill. It matches anchor 5 ('clear niche with distinct triggers') rather than anchor 4, which anticipates overlap with closely related skills.