Conciseness

The ~40-line body explains nothing Claude already knows and defers all detail to the reference; every section (Constraints, When to use, Workflow, Reference) carries operational content, matching the lean anchor-5 profile. It is not anchor 4 because the only near-redundancy (the one-line "Compile before MongoDB refactors; verify after changes" preview of the bullets) is a navigation aid, not over-explanation.

Actionability

Concrete commands are present ("Run `./mvnw compile` or `mvn compile`", "Run `./mvnw clean verify` or `mvn clean verify`") plus a real, verifiable file path, but the core implementation steps stay high-level ("Implement/refactor mappings, repositories, indexes, and failure handling policies") with specifics deferred entirely to the reference — the anchor-4 case of mostly executable guidance with minor gaps, since the referenced file does supply the executable examples.

Workflow Clarity

The four-step sequence is clearly ordered with genuine checkpoints (compile before changes, stop on failure, verify after), placing it above anchor 3. It falls short of anchor 5 because "If compilation fails, stop immediately" is a halt rather than a validate→fix→retry feedback loop, and for a database-access refactor skill the rubric specifically rewards error-recovery loops.

Progressive Disclosure

The body is a clean overview that points to exactly one reference — `references/315-frameworks-spring-mongodb.md` — which exists in the bundle, is clearly signaled both in Workflow step 1 and a dedicated Reference section, and itself contains no nested references (verified: only well-organized sections and examples), matching the anchor-5 one-level-deep structure.

Specificity

The description lists multiple concrete capability areas — "document modeling, Spring Data Mongo repositories/templates, indexing, optimistic concurrency, and error handling" — which matches the anchor-5 comprehensive example, but it opens with the second-person clause "Use when you need to design or implement", which the judging guidelines penalize by reducing specificity by 1.

Completeness

It explicitly answers both questions: the 'what' via the concrete capability list and the 'when' via "Use when you need to design or implement MongoDB data access in Spring Boot" plus "This should trigger for requests such as...", matching the anchor-5 example that pairs a what-statement with concrete trigger phrases.

Trigger Term Quality

Trigger phrases are natural and well-varied ("Add MongoDB in Spring Boot", "Review Spring Data Mongo design", "Model MongoDB documents for a Spring Boot service", "Configure Spring Data MongoDB indexes or transactions"), but common synonyms such as "NoSQL" or general persistence wording are absent, so it is good-not-comprehensive coverage per the anchor-4 example.

Distinctiveness Conflict Risk

The MongoDB-in-Spring-Boot niche is tightly scoped with distinct triggers (Spring Data Mongo, Mongo writes, MongoDB documents) that would not fire for unrelated skills; this is a clear niche with minimal conflict risk. It is not the anchor-4 case because the trigger phrases name the specific technology pair rather than a broader overlapping category.