Single tool 'query' has a minimal description (24 chars) and severely underdeveloped schema. Input schema lacks parameter descriptions entirely, the 'sql' parameter has no guidance on format, constraints, or examples. No output schema is documented. The tool lacks error handling guidance, recovery hints, and security context (e.g., how read-only is enforced, what happens on malformed SQL). No tool annotations (readOnlyHint, etc.). Naming is acceptable but description and schema quality are far below production baseline (avg description 194 chars, 100% of A+ tools have param descriptions).

• Add parameter description for 'sql': 'A SELECT-only SQL query. Must not contain INSERT, UPDATE, DELETE, or DDL statements. Example: SELECT * FROM users WHERE id = 123. Max 10,000 characters.'
• Document output schema in tool description: 'Returns an array of objects, one per result row. Each object maps column names to values. Empty array if no rows match.'
• Expand tool description to 100 - 200 chars: 'Execute a read-only SQL query against the connected MySQL database. Queries are wrapped in a READ ONLY transaction and automatically rolled back. Use this to fetch data, aggregate results, or validate conditions. Supports SELECT queries only.'
• Add error handling: catch SQL syntax errors and return 'Invalid SQL: [error detail]. Ensure query is SELECT-only and references valid table/column names.' Catch timeout errors with retry guidance.
• Add readOnlyHint annotation to tool definition: include 'readOnlyHint: true' in the tool metadata to signal to LLMs that this tool is safe to call without side effects.