This MCP SQL Server provides 7 tools with consistent naming patterns and good descriptions. All tools follow verb_noun convention (list_, get_, explore_, describe_, query_, execute_). Parameter schemas are present and mostly well-typed. However, there are critical gaps: (1) Output schemas are not documented anywhere in the provided code, LLMs cannot infer what fields to expect from tool responses; (2) Parameter descriptions lack detail about constraints, ranges, and formats, e.g., 'limit' parameters mention defaults but not why max=100 or max=1000 matters; (3) No error handling guidance visible in tool definitions, agents won't know what to do if a query fails; (4) Credentials (user, password) are exposed as optional parameters, violating secret injection patterns. The 7 tools are well-named and cover a coherent domain (SQL exploration and read-only queries), but lack the depth needed for production use.

• Document output schemas for ALL tools. For list_configured_servers, specify: 'Returns {servers: [{name: string, status: string}]}'. For execute_select_query, specify: 'Returns {columns: [string], rows: [object], row_count: integer}'. This enables LLMs to chain tool calls and extract data correctly.
• Remove user/password from tool parameters. Instead, ensure CredentialsManager and ConnectionManager load credentials from environment (MCP_SQL_USER, MCP_SQL_PASSWORD, MCP_SQL_<SERVER>_USER, etc.). Pass only the database name and server_name (which may be resolvable to credentials). This aligns with pattern:secret-injection.
• Enhance parameter descriptions with specific constraints. Replace 'Maximum number of rows to retrieve (default: 5, max: 100)' with 'Maximum rows to return. Limit prevents runaway queries on large tables. Range: 1 - 100. Default: 5.' Add rationale so LLMs understand why the limit exists.
• Add error recovery guidance to tool descriptions. E.g., execute_select_query should say: 'Validates syntax. Returns {error: string, suggestion: string} if SQL is malformed. Agent should show error to user and ask for revision.' This guides LLM error handling.
• Reduce optional parameter verbosity. Instead of 'Database user (optional, uses environment variable if not provided)', write 'Database user. If omitted, uses MCP_SQL_USER env var.' This is shorter, clearer, and avoids repetition.
• Define constraints for array parameters. For query_columns, specify: 'List of column names (1 - 50 items, non-empty). Omit for all columns.' This prevents invalid calls.