Conciseness

The body is lean with no explanation of concepts Claude already knows, but has minor duplication: the lead sentence "Compile before MongoDB refactors; verify after changes" restates the MANDATORY/VERIFY bullets, and the "When to use this skill" list repeats the description's triggers. Anchor 4 ("minor instances... that could be trimmed") fits; not 5 because those redundant lines don't each earn their place, and not 3 because there is no genuine over-explanation.

Actionability

Concrete, executable commands are present (`./mvnw compile` / `mvn compile`, `./mvnw clean verify` / `mvn clean verify`) along with an explicit reference path to read. But steps 2–3 of the workflow are abstract — "Identify model/query consistency needs and define safe improvements" — without criteria or examples of what a safe improvement looks like, matching anchor 4 (mostly executable with minor gaps) rather than 5.

Workflow Clarity

The four-step sequence is clear and gated by explicit validation checkpoints: compile MANDATORY before changes, "If compilation fails, stop immediately", and VERIFY after — a genuine feedback boundary for a database-touching refactor. It falls short of anchor 5 because there is no error-recovery loop (what to do on verify failure) and step 2 ("Gather scope and decide target improvements") is loosely defined; it exceeds anchor 3 because validation checkpoints are explicit, not implicit.

Progressive Disclosure

The body is a clean ~40-line overview (constraints, triggers, workflow) with a single, clearly signaled, one-level-deep reference — [references/415-frameworks-quarkus-mongodb.md](references/415-frameworks-quarkus-mongodb.md) — which exists on disk and contains the detailed rules and examples. No detail is inlined that belongs in the reference, and no nested references, matching anchor 5.

Specificity

The description enumerates several concrete capability areas — "Panache Mongo entities/repositories, document design, indexes, transactions where applicable, and error handling" — plus action-oriented triggers ("Add", "Review", "Improve", "Model", "Configure"), which alone would fit anchor 4. However, the judging guideline penalizes second-person voice ("Use when you need MongoDB persistence in Quarkus") by reducing specificity by 1, landing at 3. It is not 2 because the domain and multiple concrete actions are clearly named, not generic.

Completeness

Both questions are answered explicitly: the "what" ("MongoDB persistence in Quarkus — including Panache Mongo entities/repositories, document design, indexes, transactions where applicable, and error handling") and the "when" ("Use when you need MongoDB persistence in Quarkus... This should trigger for requests such as..."). This mirrors the anchor-5 example structure with concrete trigger phrases.

Trigger Term Quality

Trigger phrases read exactly like natural user requests: "Add MongoDB in Quarkus; Review Quarkus Mongo Panache design; Improve Mongo error handling in Quarkus services; Model MongoDB documents for a Quarkus service; Configure Quarkus MongoDB clients codecs or transactions". Coverage spans the domain's key nouns (MongoDB, Quarkus, Panache, codecs, transactions) and verb variations, matching the comprehensive anchor; this domain has no meaningful file extensions to include.

Distinctiveness Conflict Risk

The Quarkus + MongoDB + Panache pairing is a clear niche with distinct triggers, minimal overlap risk with generic database or Quarkus skills. "Part of Plinth Toolkit" hints at sibling skills, but every trigger term is qualified by both technologies, keeping conflict risk minimal.