This MySQL MCP server exhibits significant gaps in definition quality across multiple dimensions. While tool naming is generally clear with action verbs (mysql_query, mysql_show_*), descriptions are inconsistent in language (mixing Portuguese, Chinese, and English), and many lack the depth needed for LLM tool selection. Critically, parameter descriptions exist but are often vague regarding formats, constraints, and allowed ranges. Input schemas are present but lack critical elements like minimum/maximum bounds for numeric parameters, enums for constrained inputs (e.g., sort order, output format), and clear documentation of mutual dependencies. Output schemas are completely undocumented, LLMs have no visibility into what these tools return, preventing proper planning of downstream calls. Error handling is minimal, with generic exception classes and no actionable recovery guidance. The server lacks idempotency markers, permission declarations, and security-focused parameter validation descriptions. The code shows attempt at error handling through decorators, but errors return generic JSON without guidance on what went wrong or what the LLM should do next.

• Rewrite all descriptions in English and expand to 80 - 150 characters each. Include: WHAT the tool does, WHEN to use it instead of similar tools, and WHAT it returns. Example: 'mysql_show_columns: Retrieve metadata for all columns in a table (name, type, nullable, default). Use this before building INSERT/UPDATE statements. Returns array of column objects.'
• Document output schemas for every tool. Include example responses showing: field names, types, and sample values. For list tools, specify response structure (is it {results: [{...}], total: N} or just [{...}]?).
• Add explicit min/max/enum constraints to all numeric and string parameters in descriptions. Example: 'limit: Maximum number of results to return (1 - 1000; default 100). If 0, returns all results up to 1000.'
• Restrict mysql_query to SELECT only. Add parameter 'readonly_mode: true' with description 'If true, tool only accepts SELECT queries and rejects DDL/DML. Default true for safety.' Implement server-side validation to throw 'Only SELECT queries are allowed in readonly mode.'
• For mysql_show_variables and mysql_show_status, document in descriptions that sensitive variables (passwords, keys, certificates) are automatically filtered in production. Example: 'In production, variables containing passwords, keys, or credentials are redacted for security.'
• Clarify the distinction between mysql_show_columns and mysql_describe_table. Rename one (e.g., mysql_describe_table → mysql_show_table_definition) and document: 'Use mysql_show_columns to get individual column metadata; use mysql_show_table_definition to see the CREATE TABLE statement.'

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

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry