Conciseness

Every line is actionable routing with no concept over-explanation, but the same routing is repeated across three parallel structures: the Quick Reference table, the Decision Tree, and a ~70-line Example Invocations section that duplicates most table entries (e.g. GRDB performance and Keychain routing each appear three times). This fits anchor 3 — mostly efficient but could be tightened by collapsing to two structures — rather than anchor 2, since none of it is fluff explanation.

Actionability

Guidance is concrete and executable in form: exact file targets ("Read: `skills/database-migration.md`"), exact error strings ("errSecDuplicateItem", "FOREIGN KEY constraint failed"), and named auditors per task. Minor gaps keep it below anchor 5: the Decision Tree and Example Invocations say "Launch: `core-data-auditor` agent" while the Automated Scanning section and inline note use different skill names (`axiom-audit-core-data`), requiring a translation step, and none of the referenced `skills/*.md` targets exist in the provided bundle.

Workflow Clarity

The Decision Tree is a well-sequenced routing procedure with explicit guardrails ("ALWAYS read `skills/database-migration.md`", "CRITICAL: every local directory is purgeable"), but this skill's context is database operations, where the rubric requires validate→fix→retry feedback loops — and the body contains no validation or verification steps for its destructive-adjacent workflows (schema migrations that risk data loss), capping workflow_clarity at 3 per the rubric's feedback-loops rule.

Progressive Disclosure

The design is a clean one-level-deep index (symptom → file table plus a decision tree), which would merit a 4-5, but no bundle files are provided: the 30+ referenced `skills/*.md` paths do not exist in this skill's directory, so none of the references can be verified to resolve. Cross-skill references like "See axiom-security (skills/keychain.md)" are also ambiguous about which bundle the path lives in, fitting anchor 3 (references present and signaled, but organization/resolvability is questionable) rather than anchor 4.

Specificity

The description names the domain ("data persistence, database, storage, CloudKit, migration, or serialization in an Apple app") and enumerates technologies ("SwiftData, Core Data, GRDB, SQLite, Realm..."), but states no concrete actions — the only verb is the generic "Covers". It matches anchor 2 (names the domain but actions are minimal or generic) and falls short of anchor 3, which requires 1-2 concrete actions like extracting, migrating, or auditing.

Completeness

Both parts are present: an explicit "Use when working with ANY data persistence... in an Apple app" trigger clause, and a what-statement via "Covers SwiftData, Core Data, GRDB...". It sits at anchor 4 rather than 5 because the 'what' is a passive topic list rather than a clear statement of what the skill does (route/audit persistence work), even though the 'when' is fully explicit.

Trigger Term Quality

Strong natural keyword coverage: "database", "storage", "migration", "serialization", "CloudKit sync", plus framework names users actually say ("SwiftData", "Core Data", "GRDB", "Realm", "Codable"). Missing a few common phrasings the skill itself covers — "Keychain", "UserDefaults", "JSON" — so it fits anchor 4 (good coverage, a few natural terms missing) rather than anchor 5's comprehensive coverage with synonyms and extensions.

Distinctiveness Conflict Risk

The "in an Apple app" scoping plus named frameworks (SwiftData, Core Data, GRDB, CloudKit) establish a clear niche with minimal conflict risk. Minor overlap remains with closely related skills because the sweeping terms "ANY... storage" and "serialization" could also match general file-handling or JSON skills, fitting anchor 4 rather than anchor 5.