This MySQL tool server has critical definition quality gaps. Tool names lack action verbs (testConnection, execute, query are acceptable but insert/update/delete lack clarity on scope). Descriptions are present but generic, most are 50-100 chars, below the 194-char baseline for production tools. Parameter descriptions exist but are minimal (e.g., 'SQL 语句' for sql param). No output schemas are documented, callers cannot predict response structure. Error handling returns unstructured objects with 'success' and 'error' fields but provides no recovery guidance. The server exposes raw SQL execution, creating injection risks despite parameterization claims. No tool annotations (readOnlyHint, destructiveHint) despite clear risk levels (WRITE, DESTRUCTIVE). Composition is reasonable (7 focused tools), but parameter validation is weak, no enums, no format constraints, no min/max bounds.

• Add explicit output schemas to each tool. Document the structure of {success, data, affectedRows, insertId, error} and when each field is populated. Example: 'query returns {success: boolean, data: array<object>, error?: string}'.
• Add tool annotations to schema: set readOnlyHint=true for testConnection/query/close, destructiveHint=true for delete, and idempotentHint=true for query. This enables agents to reason about safety.
• Expand parameter descriptions to 50-150 chars. For 'sql' param: 'SQL statement (SELECT, INSERT, UPDATE, DELETE). Use ? placeholders for parameters to prevent injection. Max 10000 chars.'
• Add input validation constraints: declare 'table' as a string matching ^[a-zA-Z_][a-zA-Z0-9_]*$ (identifier pattern), 'params' as array<any> with maxItems=100, 'data' as object with minProperties=1.
• Enhance error responses with recovery guidance. Instead of {success: false, error: 'SQL syntax error'}, return {success: false, error: 'SQL syntax error: unexpected token at position 42', recoveryHint: 'Check query syntax or use parameterized queries (?)', retryable: false}.