MySQL MCP Server presents a functional database toolkit with 8 well-structured tools for connection management and SQL execution. Strengths include complete JSON Schema definitions for all tools, consistent parameter descriptions, and clear action verbs in tool names. However, significant gaps emerge in output schema documentation (no documented return types visible), error guidance (errors are generic without recovery paths), and tool composition (missing idempotency guarantees and transaction support). Tool descriptions are adequate but lack depth on when to use each tool vs alternatives. Parameter validation is present but descriptions could be more explicit about constraints and ranges. Output structures are not documented, forcing LLMs to infer response formats. The server lacks patterns for confirmation before destructive operations (remove_connection, execute_query with DELETE/UPDATE).

• Document output schema for every tool. Example for execute_query: {type: 'object', properties: {rows: {type: 'array', items: {type: 'object'}}, affected_rows: {type: 'integer'}, execution_time_ms: {type: 'integer'}}, required: ['rows']}
• Add error recovery guidance. Modify tool error responses from '❌ 执行失败: Connection timeout' to 'Connection timeout (retryable). Call list_connections to verify availability, or wait 30s and retry.'
• Implement confirmation pattern for destructive tools. Add 'confirm=true' parameter to remove_connection and execute_query. Return 'This will remove connection 'prod'. Retry with confirm=true to proceed.' on first call without confirmation.
• Clarify state dependencies in descriptions. Add to select_database and tools that use it: 'Affects all subsequent calls in this session until changed. Always verify which connection is active before executing mutations.'
• Document execute_query constraints explicitly. Add to description: 'Max 100KB per statement. Results capped at 10000 rows. Supports SELECT/INSERT/UPDATE/DELETE. Parameterized queries recommended (pass query params in separate tool parameter to avoid SQL injection).'
• Add pagination to list_connections, show_tables, show_databases. Include optional 'limit' (default 20, max 100) and 'offset' parameters. Return {items: [...], total: N, has_more: bool} instead of all results.
• Rename execute_query to clarify intent. Consider 'query_database' (signals read focus) or split into 'execute_read_query' and 'execute_write_query' for different risk profiles.

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

• Relies on Stateful initialize / Mcp-Session-Id (removed; protocol is stateless) - make each request self-contained