Conciseness

The body is lean: 21 one-line directives with concrete banned phrases, no explanations of concepts Claude already knows. Minor trimmable content remains — the maintainer-facing 'Updating' section (~8 lines) and the meta note 'Frontmatter metadata is scanned eagerly at session start' do not serve the invoking agent. This is anchor 4 (efficient, minor instances that could be trimmed), not anchor 5, and well above anchor 3.

Actionability

For an instruction-only skill the guidance is fully concrete: each rule pairs a directive with specific tokens ('in order to', 'pushes the boundaries', 'use' over 'leverage', 'proves' vs 'suggests'); the handshake gives a verbatim reply string; the CLI path is executable ('uv tool install agent-style', 'agent-style audit FILE'); and the reference resolution order names real paths. Matches anchor 5 — copy-paste-ready, specific direction covering the common cases.

Workflow Clarity

A simple single-purpose skill whose core action (apply the 21 rules when revising prose) is unambiguous, with a clearly sequenced 3-step resolution order for locating full rule bodies (project root → vendored snapshot → upstream). It falls short of anchor 5 because it never says when the compact directives suffice versus when to consult the full rule bodies in references/RULES.md. No destructive or batch operations, so no validation cap applies.

Progressive Disclosure

The body is a compact overview while the 814-line full rule set is appropriately externalized to references/RULES.md (verified to exist), alongside UPSTREAM-PIN, NOTICE.md, and LICENSES/CC-BY-4.0.txt — all real, one level deep, and clearly signaled with an explicit resolution order. The one out-of-bundle path (scripts/update-upstream.sh) is explicitly scoped to the plugin root as maintainer context, not navigation, so it does not break the structure. Matches anchor 5.

Specificity

The description names the domain and artifact concretely ('Literature-backed English technical-prose writing rules (agent-style, 21 rules)', 'papers, design docs, proposals, READMEs, commit messages') but never states the skill's actions in its own words — the verbs only appear inside quoted user trigger phrases. This matches anchor 3 (domain plus 1-2 implied actions, not comprehensive); anchor 4 requires several specific actions listed by the skill itself.

Completeness

It explicitly answers both questions: what ('Literature-backed English technical-prose writing rules... Its lane is FORMAL technical prose') and when ('Use ONLY when the user explicitly asks for agent-style by name (e.g. "apply agent-style"...)'), with concrete trigger phrases. This is the anchor-5 pattern; it exceeds anchor 4 because the when-clause is maximally explicit with example phrasings.

Trigger Term Quality

It quotes natural user phrasings verbatim ('apply agent-style', 'write/revise this per agent-style rules', 'iterate until agent-style clean') plus concrete domain nouns (papers, design docs, commit messages). Good coverage but natural synonyms a user might say ('formal writing style', 'tighten this prose') are absent — deliberately gated to the skill name, which fits anchor 4 rather than the comprehensive synonym coverage of anchor 5.

Distinctiveness Conflict Risk

It is explicitly gated ('Use ONLY when the user explicitly asks for agent-style by name'), disambiguates against a named sibling skill ('NOT for de-AI-ing casual or voiced text — use remove-ai-patterns for that'), and forbids auto-triggering ('Do not auto-trigger for ordinary prose or documentation tasks'). Clear niche with distinct triggers and minimal conflict risk — anchor 5.