Conciseness

The body is lean: short PASS/FAIL code blocks and terse bullets, with no padding explaining what Java or Spring Boot is, assuming Claude's competence. It is not 5 because the '核となる原則' section restates principles that recur in later sections, a minor instance of over-explanation that could be trimmed.

Actionability

Examples are concrete, real Java (record definitions, Optional.map/orElseThrow, stream pipelines, bounded-generics indexById), giving mostly executable guidance. It is not 5 because several snippets are intentionally partial (empty method bodies like `findBySlug(String slug) {}` and `{ ... }` placeholders), leaving minor gaps.

Workflow Clarity

As a single-purpose reference skill the 'action' (apply these standards) is unambiguous and the sections are well-organized, qualifying for the simple-skill exception; no destructive or batch workflow is present so the cap at 3 does not apply. It is not 5 because there is no sequenced process or validation checkpoint, only topical organization.

Progressive Disclosure

The content is well-structured with clear section headers and no nested or buried references, and no external files are needed. It is not 5 because the body exceeds the ~50-line simple-skill threshold and several sections (e.g. project structure, test expectations) could optionally be split into one-level-deep reference files.

Specificity

Names the domain ('Spring Bootサービス向けのJavaコーディング標準') and lists several concrete coverage areas (命名、不変性、Optional使用、ストリーム、例外、ジェネリクス、プロジェクトレイアウト), giving broad but topic-level rather than action-level coverage. It sits above 3 (which requires only 1–2 concrete actions) but the items are topical areas rather than the explicit concrete actions a 5 demands.

Completeness

The 'what' is clear (Java coding standards for Spring Boot services with enumerated topics), but there is no 'Use when...' clause or equivalent explicit trigger guidance, which per the judging guidelines caps completeness at 3. It is not 2 because the 'what' is concrete and specific rather than vague.

Trigger Term Quality

Natural terms a user would say are present ('Spring Boot', 'Java', 'コーディング標準', 'ストリーム', 'ジェネリクス'), giving good keyword coverage. It is below 5 because common synonymous phrasings users might say (e.g. 'コード規約', 'レビュー', 'Spring Boot conventions') are not covered.

Distinctiveness Conflict Risk

The 'Spring Bootサービス向け' framing carves a clear niche distinct from generic Java or language-agnostic skills, with minor overlap risk against broader Java coding-standards skills. It is not 5 because the topic list (naming, exceptions, generics) overlaps with general Java style guides.