Conciseness

The body is lean: a six-step workflow table, a reference routing table, compact copy-paste code, and MUST DO / MUST NOT constraint tables — with zero padding explaining what Spring Boot or Spring concepts are. Every section carries rules or code Claude does not already know, matching anchor 5 ("lean and efficient; assumes Claude's competence") rather than anchor 4, which would require trimming instances of over-explanation.

Actionability

The Quick Start provides a fully executable vertical slice — Entity, Repository, Service, Controller, DTO record, GlobalExceptionHandler, and a runnable @WebMvcTest — plus concrete commands like `./mvnw test` and `/actuator/health`. This is copy-paste ready code covering the common case, matching anchor 5; anchor 4 would imply minor gaps in executability, which are absent.

Workflow Clarity

The Core Workflow is a clear six-step sequence with explicit validation checkpoints and feedback loops: "verify security rules compile and pass tests. If compilation or tests fail: review error output, fix... and re-run", "run `./mvnw test`... If tests fail: review the stack trace, isolate... fix, and re-run", and "validate `/actuator/health` returns `UP`. If health is `DOWN`: check the `components` detail... and re-validate". This mirrors the anchor-5 validate → fix → retry exemplar; anchor 4 would require missing checkpoints, and none are missing.

Progressive Disclosure

SKILL.md is an overview: the Reference Guide table routes to five topic files (web.md, data.md, security.md, cloud.md, testing.md), all of which exist, are one level deep, contain no further nested .md references, and are signaled with a "Load When" column. Combined with detailed content appropriately split out of the body, this matches anchor 5 ("clear overview with well-signaled one-level-deep references; easy navigation").

Specificity

The description lists multiple specific concrete actions — "Generates Spring Boot 3.x configurations", "creates REST controllers", "implements Spring Security 6 authentication flows", "sets up Spring Data JPA repositories", "configures reactive WebFlux endpoints" — with comprehensive coverage across the skill's domain. It clearly matches the anchor-5 example ("Lists multiple specific concrete actions; comprehensive coverage") and is nowhere near anchor 4, which would require minor coverage gaps.

Completeness

It explicitly answers both questions: what (the five concrete actions) and when ("Use when building Spring Boot 3.x applications, microservices, or reactive Java applications; invoke for Spring Data JPA, Spring Security 6, WebFlux..."). This mirrors the anchor-5 exemplar almost exactly, and the explicit "Use when..." clause means it is well above anchor 4's weaker 'when'.

Trigger Term Quality

Natural trigger terms a user would actually say are comprehensively covered: "Spring Boot 3.x applications", "microservices", "reactive Java applications", "Spring Data JPA", "Spring Security 6", "WebFlux", "Spring Cloud integration", "Java REST API design". Coverage includes framework-specific synonyms and version markers, matching the anchor-5 "comprehensive coverage of natural terms" rather than anchor 4, which requires noticeable missing terms.

Distinctiveness Conflict Risk

The core niche (Spring Boot 3.x Java backend) is clear and mostly distinct, but broader trigger phrases like "Java REST API design" and "Microservices Java architecture" overlap with closely related skills (the metadata itself lists java-architect and microservices-architect), fitting anchor 4 ("minor overlap risk with closely related skills") better than anchor 5's "minimal conflict risk".