docs(skill): clarify SQL skill triggers

shared/skills/implementation/sql-write/SKILL.md

@@ -1,12 +1,19 @@
 ---
 name: sql-write
-description: Implement a focused SQL change safely.
+description: Use when writing or modifying SQL queries, schema, database migrations, or data updates; account for dialect, compatibility, authorization, and data safety.
 ---
 
 # SQL Write
 
-Understand the schema and affected data before writing SQL.
+Use when writing or changing SQL statements, schema definitions, or database migrations.
 
-Use the smallest complete change, preserve data safety, and run relevant verification.
+## Workflow
 
-Do not execute destructive operations without explicit authorization.
+1. Identify the database engine and version, target schema, affected callers, and expected data shape. Inspect existing migrations and SQL style first.
+2. Parameterize values and validate any dynamic identifiers against an allowlist. Preserve tenant boundaries and authorization filters in every query path.
+3. For schema changes, consider existing rows, nullability, defaults, constraints, indexes, and deployment order. Prefer additive, backward-compatible steps when old and new application versions may overlap.
+4. Use transactions and explicit rollback or recovery steps where supported and appropriate. Estimate affected rows before broad updates or deletes.
+5. Do not execute destructive or production SQL without explicit authorization. A request to write SQL does not authorize running it against live data.
+6. Verify syntax and behavior against the intended engine, then inspect query results, migration ordering, and relevant application tests.
+
+Report the database dialect, files or migration changed, verification, and any operational prerequisite.