Single tool 'query' has critical definition gaps. Description is minimal (28 chars, below 20-char floor). Input schema present but parameter 'sql' lacks description entirely, violates pattern:tool-description. No output schema documented. No error handling guidance. No parameter constraints (e.g., query size limits, timeout). Tool does not follow verb_noun naming (should be 'execute_query' or 'run_query'). No indication of what fields are returned or how to chain results to other tools.

• Add detailed parameter description for 'sql': 'SQL SELECT statement (read-only). Max 10,000 chars. Supports WHERE, JOIN, GROUP BY, ORDER BY, LIMIT. Timeout: 30s. Example: SELECT * FROM users WHERE active = true LIMIT 10'
• Expand tool description to 100-150 chars: 'Execute a read-only SQL query against the connected PostgreSQL database. Returns rows as JSON objects. Use for data retrieval, aggregation, and analysis. Queries run in READ ONLY transactions and cannot modify data.'
• Document output schema in description: 'Returns an array of objects where each object represents a row. Fields depend on the SELECT clause. Example: [{"id": 1, "name": "Alice"}, ...]'
• Add input validation and error messages: catch SQL errors and return 'Invalid SQL syntax: [specific error]. Ensure query is SELECT-only and valid PostgreSQL.' instead of throwing.
• Add parameter constraints to schema: set maxLength on 'sql' (e.g., 10000), document timeout (30s), and clarify that only SELECT statements are allowed (no INSERT, UPDATE, DELETE).