Conciseness

Phrases like 'The dump's version stamp should match the change's newest migration' and 'The fix is expand and contract: add, migrate readers and writers, remove only once nothing reads the old shape' deliver dense, non-redundant expertise with zero padding or explanation of concepts Claude already knows. Every line is either a check, a method step, a threshold rule, or a reporting instruction.

Actionability

The body gives concrete, executable commands ('git checkout <base> -- db/schema.rb', 'rerun bin/rails db:migrate', 'Diff the dump and db/migrate/ against the review's base ref, never an assumed main') plus specific inspection techniques ('Check each CASE or IF branch and constant hash entry individually'). It falls short of 5 because the reporting section says 'give sample read-only SQL that would prove it' without providing a sample, and not 3 because the guidance is directly executable as written, not pseudocode.

Workflow Clarity

The Method section gives an explicit ordered sequence ('check drift first... Then check migration correctness, then verification and rollback') with a guardrail ('Do not trust fixtures; production data shapes differ'), and the Threshold section acts as a report/don't-report checklist. This is a single-purpose, read-only review skill under 50 lines, so the simple-skill exception applies and no destructive-operation cap is triggered since the skill only reviews, never performs, destructive changes.

Progressive Disclosure

The skill is under 50 lines with no need for external references (no references/, scripts/, or assets/ bundle exists), and its content is organized into clear, well-labeled sections (Scope, Method, Threshold, Reporting). Per the rubric guideline, this earns a 5 with just well-organized sections.

Specificity

The description enumerates eleven concrete, distinct checks: 'schema dump drift, swapped ID or enum mappings, irreversible migrations, missing backfills, deploy-window breaks, orphaned references, broken dual-writes, missing transactions, unsafe hot-table indexes, silent data loss, and missing post-deploy verification'. This is comprehensive coverage of the migration-review domain, matching the score-5 anchor; it exceeds 4 because the action list is exhaustive rather than having minor gaps.

Completeness

It explicitly answers both questions: the long check list states exactly what the skill does, and 'Use when reviewing database migrations, schema changes, or data backfills' states when to invoke it with concrete trigger phrases. This matches the score-5 anchor verbatim in structure.

Trigger Term Quality

The 'Use when' clause includes natural terms users would say: 'reviewing database migrations, schema changes, or data backfills'. It falls short of 5 because common variations are missing — users also say 'migration files', 'schema.rb', 'ALTER TABLE', or 'data integrity' — but coverage is solidly good, not just 'some relevant keywords'.

Distinctiveness Conflict Risk

The opening 'Review a code change for schema dump drift...' is a clear niche (database migration review), and the 'Use when reviewing database migrations, schema changes, or data backfills' trigger clause keeps it distinct from generic code-review skills. Terms like 'schema dump drift' and 'broken dual-writes' are unmistakably this skill's territory, minimizing conflict risk.