mcp-datalink exhibits solid definition quality with well-structured schemas and clear descriptions for all 6 tools. All tools are explicitly registered with complete inputSchemas including type definitions and parameter descriptions. Tool names follow verb-noun conventions appropriately (list_*, describe_*, query, execute, explain). Descriptions are substantive (ranging 40-160 chars) and action-oriented. However, there are notable gaps: no tool annotations (readOnlyHint/destructiveHint/idempotentHint), limited output schema documentation, and missing error recovery guidance. The execute tool description lacks explicit warning about state mutation consequences. Several parameter descriptions reference example values that could be reused literally by LLMs (e.g., 'Example: ["active", "2024-01-01"]'). All tools carry good parameter validation constraints (timeout ranges 5000-600000ms), but the response format for multi-row result sets is not formally documented.

• Add tool annotations: destructiveHint=true for execute; readOnlyHint=true for list_databases, list_tables, describe_table, query, explain. This guides agent safety policies and call sequencing.
• Replace example parameter values with formal schema constraints. For the 'analyze' boolean in explain, use type: boolean with default: false rather than descriptive text.
• Document the output schema for query and execute tools. Example: 'Returns {rows: Array<Record<string, any>>, rowCount: number, columns: Array<{name: string, type: string}>}' or similar. For pagination, specify if results are capped and how to request more.
• Enhance the execute tool description with explicit state-mutation language: 'Executes an INSERT, UPDATE, or DELETE query. This operation is irreversible and will modify the database. Returns the number of affected rows. Use with caution in production.'
• Add recovery guidance to query, execute, and describe_table descriptions. Example: 'If the query fails, verify table and column names by calling describe_table. If the table is not found, call list_tables to discover available tables.'
• Clarify the params parameter: if SQL contains $1 placeholders, params should be required. Add a constraint like 'array length must match the number of placeholders in sql'. Validate at runtime and return a clear error message if count mismatches.
• Consider adding a batch_query or batch_execute tool for agents that need to run multiple SQL statements in sequence, reducing round-trips and improving token efficiency.