The Metabase MCP server provides 6 well-named tools with clear descriptions and structured schemas. Tool naming consistently follows verb_noun patterns (get_schema, list_collections, run_query, save_question). All tools have non-empty descriptions (79-155 chars, within baseline 34-392 range). Input parameters include type definitions and descriptions. However, there are significant gaps: (1) No output schemas are documented, the descriptions state WHAT tools do but not what fields/structure they return, forcing LLMs to guess response structure; (2) Parameter descriptions lack guidance on dependencies (e.g., save_question has both database_id and collection_id but no clarification on mutual exclusivity or defaults); (3) Error handling is not visible in tool definitions, descriptions don't explain recovery paths or failure modes; (4) The raw_api tool is a security concern, offering unrestricted API access without visible safeguards. Overall, this is a competent but incomplete implementation that would benefit from output schema documentation and better error guidance.

• Document the return schema for each tool. For list_collections and list_databases, specify the structure of collection/database objects (id, name, description, created_at fields). For get_schema, document the table/field object structure. For run_query, clarify the result format (rows array with column/value pairs? objects with column names as keys?). For save_question, confirm the response includes question_id for downstream references.
• Add explicit error guidance to tool descriptions. E.g., run_query: 'If the SQL query fails, the error will indicate the syntax error or missing table. Use get_schema first to verify available tables.' save_question: 'If collection_id is invalid, an error will list available collections.'
• Restrict raw_api with explicit path allowlist or sandbox rules. Describe which endpoints are safe (e.g., /api/database, /api/collection) vs. prohibited (/api/user/delete). Add rate limiting and audit logging requirements to the description.
• Clarify parameter defaults and mutual exclusivity in save_question. E.g., 'collection_id: Optional. If omitted, saves to your personal collection. Cannot be changed after creation.' Add explicit note: 'database_id is required; collection_id is optional.'
• Add constraints to run_query output_file: 'Relative paths are relative to the Metabase data directory. Use forward slashes. Absolute paths are prohibited for security.'
• For get_schema, document case sensitivity and error handling: 'Table names are case-insensitive. If a table is not found, an error lists all available tables.'