Conciseness

Nearly every section carries project-specific rules Claude could not infer (checksum immutability, the Spring Boot 4 vs 3 Flyway starter split, Flyway 10 database modules) and it assumes SQL competence, but the prompt-injection paragraph and the repeated /use-case-implement rules in 'Run Directly' could be tightened, leaving a few over-explained spots.

Actionability

Guidance is fully executable: a complete example migration, file-naming examples, the exact marker comment format, migration-location resolution rules, and a copy-paste Handover template with concrete coordinates and module paths.

Workflow Clarity

The 9-step workflow has an explicit validation checklist (step 7) and guards destructive operations ('drops a table or a column without explicit confirmation'), but for database operations the error-recovery loop — what to do when validation fails — is implicit rather than a validate/fix/re-validate cycle, so it falls between the sequence-with-checkpoints and full-feedback-loop anchors.

Progressive Disclosure

The body is well sectioned and its one reference link, references/markers.md, is clearly signaled and exists in the bundle; however references/layer.md is present but unlinked from the body, and the ~200-line body keeps some peripheral detail (the classpath version matrix) inline, leaving minor organization gaps rather than a fully clean overview-to-reference split.

Specificity

The description enumerates concrete actions — 'versioned V*.sql scripts with sequences, tables, snake_case columns, CHECK and UNIQUE constraints, and foreign keys from the entity model' plus marker commenting — comprehensive rather than leaving minor gaps, matching the level-5 anchor.

Completeness

It explicitly answers what (builds the migration layer with the listed artifacts) and when ('Use when the user asks to…' with concrete trigger phrases), matching the anchor for both what and when with explicit triggers.

Trigger Term Quality

It quotes natural user phrases ('create a migration', 'write a Flyway migration', 'add a column', 'create the tables for UC-001', 'set up the database schema') alongside synonyms (schema migration, DB migration, database versioning, SQL migration files), giving comprehensive keyword coverage.

Distinctiveness Conflict Risk

The Flyway/UC-layer niche is clear and it draws an explicit boundary ('Test data migrations belong to the test skills'), but generic triggers like 'add a column' and 'set up the database schema' leave minor overlap risk with closely related persistence or schema-setup skills, so it sits just below the minimal-conflict anchor.