Conciseness

Nearly every section carries project-specific rules Claude could not infer (migration location precedence, Spring Boot 4 vs 3 starters, naming conventions), with no explanation of basic concepts. It stops short of level 5 because of redundancy: the checksum rationale ("Flyway checksums applied scripts") appears in both Instructions and DO NOT, and DO NOT restates Schema Conventions items ("Use auto-increment or identity columns", "camelCase", "Write test data").

Actionability

Fully executable throughout: a complete example migration (CREATE SEQUENCE room_type_seq..., named constraints room_type_name_uk, room_type_capacity_ck), exact dependency coordinates ("spring-boot-starter-flyway", "org.flywaydb:flyway-database-postgresql"), concrete naming patterns ("V001__create_room_type_table.sql", "CONSTRAINT {table}_{column}_{uk|ck|fk}"), and a copy-paste Handover template covering the common cases including 'Build: missing' and 'Nothing to do'.

Workflow Clarity

The 9-step Workflow is clearly sequenced with an explicit validation checkpoint (step 7's checklist) and a feedback loop: "When a check or the build fails, fix the new migration — it has not run anywhere yet — and repeat this step until both pass." Destructive operations are guarded ("Create a migration that drops a table or a column without explicit confirmation from the user"), meeting the level-5 anchor with validation, error recovery, and a checklist.

Progressive Disclosure

Both bundle files exist and are well-signaled one level deep: references/markers.md ("[references/markers.md](references/markers.md)") and references/layer.md (described in Resources as "this skill's row of the layer catalog"); neither points further into the bundle. It sits at level 4 rather than 5 because the ~240-line body inlines reference-shaped material — notably the Spring Boot 3/4 and Flyway 10 dependency lookup table in 'Flyway on the Classpath' — that could live in a reference file with a pointer.

Specificity

Lists multiple concrete, comprehensive actions: "versioned V*.sql scripts with sequences, tables, snake_case columns, CHECK and UNIQUE constraints, and foreign keys from the entity model", "ALTER TABLE only where an existing table lags behind the entity model", and the concrete marker syntax "-- UC-XXX BR-YYY". Nothing is generic; it matches the 'multiple specific concrete actions; comprehensive coverage' anchor, not the level-4 anchor with 'minor gaps in coverage'.

Completeness

Explicitly answers both questions: what ("Builds the migration layer of a use case (UC-XXX) with Flyway: versioned V*.sql scripts...") and when ("Use when the user asks to 'create a migration'..."). This is the level-5 pattern of a clear 'what' plus a concrete 'Use when' clause with trigger phrases; the level-4 anchor's 'when could be more explicit' does not apply.

Trigger Term Quality

Quotes natural user phrasings directly — "create a migration", "write a Flyway migration", "add a column", "create the tables for UC-001", "set up the database schema" — and adds the synonyms "schema migration, DB migration, database versioning, or SQL migration files". Coverage including variations matches the level-5 anchor rather than the level-4 anchor that misses a few natural terms.

Distinctiveness Conflict Risk

A clear niche (Flyway schema migrations for use cases) with distinct, technology-specific triggers, plus explicit boundaries: "Test data migrations belong to the test skills" and "in a project that combines layer plugins". Minimal conflict risk, matching the level-5 'clear niche with distinct triggers' anchor rather than level 4's 'minor overlap risk'.