Single tool 'mysql_query' has a reasonable description (89 chars) but critically lacks parameter descriptions. The input schema defines only 'sql' as a string with minimal guidance. No output schema is documented. The tool is destructive (INSERT, UPDATE, DELETE, DDL) but lacks error handling guidance, recovery patterns, or confirmation mechanisms. No tool annotations (readOnlyHint/destructiveHint) present. The description mentions multi-DB and schema-specific permissions but does not explain when to use this tool vs alternatives, what it returns, or how to handle failures. Parameter 'sql' has no format constraints, length limits, or injection-prevention guidance despite being a SQL injection vector.

• Add detailed parameter description for 'sql': 'SQL query to execute (SELECT, INSERT, UPDATE, DELETE, or DDL). Must be valid MySQL syntax. Queries are validated against schema-specific permissions (INSERT/UPDATE/DELETE/DDL). Example: SELECT * FROM users WHERE id = 123. Do NOT construct queries by string concatenation, use parameterized queries to prevent SQL injection.'
• Document output schema: 'Returns an object with: { success: boolean, data: array of objects (for SELECT) or { affectedRows: number, insertId?: number } (for INSERT/UPDATE/DELETE), error?: string, executionTime: number }. For SELECT queries, each row is an object with column names as keys.'
• Add tool annotations to schema: 'destructiveHint: true' (for INSERT/UPDATE/DELETE/DDL), 'idempotentHint: false' (queries may have side effects). This signals to LLMs that retries are unsafe.
• Implement dry-run pattern: Add optional 'dry_run: boolean' parameter. When true, return the query plan and affected row count WITHOUT executing. Allows LLM to preview changes before committing.
• Add error handling guidance to description: 'On permission denied, returns error with required schema permissions. On syntax error, returns the invalid query and MySQL error message. On timeout (>30s), returns timeout error with retry guidance. On connection failure, returns connection error, check MYSQL_HOST and credentials.'

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry