Names the domain (SQL database) and lists some actions (design, query optimization, migration safety), but doesn't provide comprehensive concrete actions like specific techniques or operations (e.g., 'create indexes', 'normalize tables', 'write rollback scripts').

Clearly answers both what ('SQL database design, query optimization, and migration safety') and when ('Use when writing queries, designing schemas, or planning database migrations') with explicit trigger guidance.

Includes natural keywords users would say: 'queries', 'schemas', 'database migrations', 'SQL'. These are terms users naturally use when seeking database help.

Clear niche focused on SQL databases with distinct triggers (schemas, migrations, query optimization). Unlikely to conflict with general coding skills or document processing skills.

The skill is relatively brief but includes boilerplate sections (Troubleshooting, Examples) that are generic and don't add database-specific value. The actual database guidance is minimal - just one principle about UNION ALL.

Extremely vague - provides only one concrete tip (UNION ALL over UNION) with no executable SQL examples, no schema patterns, no migration commands, and no query optimization techniques despite the description promising all of these.

The workflow section is generic meta-instructions about skill usage, not actual database workflow steps. No validation checkpoints for migrations, no rollback procedures, no zero-downtime deployment sequence despite the example mentioning this use case.

References a rules index file which is appropriate structure, but the main file contains almost no substantive content to serve as an overview. The balance is inverted - too little here, presumably everything in the referenced file.