Conciseness

The body is lean and dense — nine terse glossary entries, compact principles, no padding — matching anchor 4 (efficient, minor instances that could be trimmed). It is not a 5 because the "Testable / Hard to test" TypeScript snippets re-teach dependency injection, a concept Claude already knows, though the surrounding framing in terms of the vocabulary keeps the over-explanation minor.

Actionability

Concrete, usable decision rules are given — "the deletion test", "One adapter means a hypothetical seam. Two adapters means a real one", the three-question interface checklist, and executable TypeScript examples — matching anchor 4 (mostly executable guidance with minor gaps). Not 5 because the guidance is judgment criteria for a vocabulary skill rather than copy-paste-ready instruction covering common cases end-to-end, and not 3 because nothing is pseudocode or vague.

Workflow Clarity

Organization is coherent and navigable (glossary, deep vs shallow, principles, testability application, relationships) with an explicit design checklist; there is no multi-step process to sequence and no destructive or batch operation that would require validation. Anchor 4 fits (clear structure, minor gaps); 5 is reserved for an explicit validated sequence, and the 115-line body with no step sequence for applying the vocabulary to a concrete design task falls short of that.

Progressive Disclosure

The "Going deeper" section signals one-level-deep references clearly and the main body is well organized, but both referenced files (DEEPENING.md and DESIGN-IT-TWICE.md) are absent from the bundle — neither references/ nor any other directory contains them — so both navigation paths are dangling. Anchor 3 (structure present but navigation does not actually work) fits better than anchor 4, where gaps would be minor; a fully broken two-link "Going deeper" section is more than a minor organization gap.

Specificity

The when-clause lists several concrete actions — "design or improve a module's interface, find deepening opportunities, decide where a seam goes, make code more testable or AI-navigable" — which sits at anchor 4 (several specific actions, minor gaps). It falls short of 5 because the what-clause ("Shared vocabulary for designing deep modules") is a single capability and no full inventory of actions is given, but exceeds 3 because more than 1-2 concrete actions are explicitly named.

Completeness

"Shared vocabulary for designing deep modules" explicitly states what the skill provides, and "Use when the user wants to... find deepening opportunities, decide where a seam goes... or when another skill needs the deep-module vocabulary" explicitly answers when with multiple concrete trigger phrases. This matches anchor 5 and is above anchor 4, where the when would be less explicit or specific.

Trigger Term Quality

Natural phrases a user would actually say are present ("improve a module's interface", "make code more testable", "design"), alongside distinctive terms like "deepening" and "seam". Coverage is good but misses common synonyms users might say instead ("refactor", "decouple", "architecture"), placing it at anchor 4 rather than 5, and clearly above 3 since multiple natural variations are covered.

Distinctiveness Conflict Risk

Niche terms ("deep module", "seam", "deepening opportunities") create a distinctive profile, but "design or improve a module's interface" overlaps with generic refactoring/architecture skills — anchor 4 (mostly distinct, minor overlap risk) rather than 5. It is well above anchor 3 because the deep-module vocabulary is not interchangeable with adjacent skills.