Universal Database MCP has 4 tools with basic schemas and descriptions, but significant quality gaps. Tool names are adequate (verb_noun pattern followed), but descriptions are inconsistent in quality and depth. Parameter descriptions exist but lack detail on constraints, valid formats, and error conditions. Output schemas are largely undocumented, no structured response definitions are visible in the source. Error handling is minimal. The execute_query tool accepts arbitrary SQL with only loose parameterization guidance, creating security concerns. Overall, this server falls into the 'poor' category (D grade) with major gaps in parameter documentation, output schema clarity, and error guidance.

• Document output schemas for all tools. For execute_query, specify: { rows: Array<Record>, affectedRows?: number, executionTime: number }. For get_schema, specify: { tables: Array<{ name, columns: Array<{ name, type, nullable }>, indexes: Array<...> }> }.
• Add error classification and recovery guidance to execute_query description. Example: 'On syntax error, return the error message and suggest checking the SQL. On connection timeout, the agent should retry. On permission denied, ask the user to verify database credentials.'
• Add constraints to parameters. Execute_query.query: document max length, disallowed operations in read-only mode. get_table_info.tableName: accept a 'list_tables' tool as a prerequisite, or return available tables in error responses.
• Clarify the distinction between get_schema and get_table_info in descriptions. Schema returns all tables; table_info returns details for one table. Add: 'Call get_schema to discover available tables; call get_table_info to inspect one table's columns and indexes.'
• Add tool annotations to the MCP protocol response. Mark execute_query with destructiveHint=true if write mode is enabled. Mark get_schema and get_table_info with readOnlyHint=true.
• Document parameterization mechanism in execute_query. Clarify that the 'params' array is bound safely (prepared statement style), not string-interpolated. Specify which databases support this (e.g., MySQL uses ?, PostgreSQL uses $1, SQL Server uses @param0).
• Add result limits and pagination guidance. If execute_query can return thousands of rows, document the limit and offer offset/limit parameters.