Conciseness

The bullet style is dense and assumes competence, but there is noticeable duplication (e.g., "Use early returns to reduce nesting" beside "Use early returns or extraction when nesting obscures..."; "After identifying actual bottlenecks through profiling" beside "Optimize only after measurable bottlenecks are identified") and several bullets restate basics Claude already knows ("Each function should do one thing well", "Use proper grammar and formatting"), fitting anchor 3 (mostly efficient but could be tightened) more than anchor 2's padded sections or anchor 4's minor trims.

Actionability

Many directives are concrete ("Inject external dependencies as parameters", "Use parameterized queries (prepared statements) for all database access"), but there are no illustrative examples at all and sections like "Reference Representativeness" remain abstract prose, matching anchor 3 (some concrete guidance but incomplete, missing key details) rather than anchor 4's mostly-executable guidance with only minor gaps.

Workflow Clarity

This is a principles reference with no multi-step process to sequence and no risky operations requiring validation, so no cap applies, but the simple-skill exception (under 50 lines, single task) does not apply to a ~170-line multi-topic document; topical organization is clear yet no workflow or checkpoints exist, landing on anchor 3.

Progressive Disclosure

Both bundle files (references/security-checks.md, references/frontend.md) exist, are referenced one level deep, and carry clear signals (inline pointer in the Security section; a References section with a when-to-read trigger), matching anchor 4; dense fully-inlined sections like "Reference Representativeness" and generic inline security principles keep it from anchor 5's clean overview split.

Specificity

The description names the domain ("coding principles") and three concrete focus areas ("maintainability, readability, and quality") but states no concrete actions the skill performs, matching anchor 3 (domain plus some specifics, not comprehensive) rather than anchor 2's bare domain naming or anchor 4's list of specific actions.

Completeness

It explicitly answers both questions: the what is "Language-agnostic coding principles for maintainability, readability, and quality" and the when is an explicit "Use when..." clause listing three concrete triggers, matching anchor 5; anchor 4 would require the when to be less explicit or specific, which it is not.

Trigger Term Quality

"Use when implementing features, refactoring code, or reviewing code quality" supplies natural phrases users would say, but common synonyms such as "clean code", "code smells", or "best practices" are absent, fitting anchor 4 (good keyword coverage, a few natural terms missing) rather than anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

The domain is somewhat specific (quality/maintainability principles with a code-review trigger), but "implementing features" would fire for nearly any coding request and the skill overlaps with code-review and language-specific style skills, matching anchor 3 rather than anchor 4's minor overlap risk.