Single tool with minimal definition quality. Tool name 'create_note' follows verb_noun convention (+), but description is extremely terse (18 chars, well below 34-char p10 baseline). Input schema is present with proper JSON Schema structure and required fields, but parameter descriptions are minimal (8-19 chars each, far below 72-char baseline). No output schema documented. No error handling guidance. Tool lacks context about when to use it, what it returns, or recovery paths. Composition is simple (one tool, one action), but lacks the depth expected for production use.

• Expand tool description to 50-150 chars explaining: what it does (creates a note in Feishu), when to use it (when user wants to record information), and what it returns (success confirmation with note ID). Example: 'Create a new note in Feishu Base. Returns the created note ID and confirmation. Use this when the user wants to save information for later reference.'
• Add detailed parameter descriptions: title → 'The note title (1-200 characters, required). Used as the heading in Feishu Base.' content → 'The note body text (1-5000 characters, required). Supports plain text; markdown not supported.'
• Document the output schema in the tool description: 'Returns {success: boolean, note_id: string, created_at: ISO8601 timestamp, message: string}'. Include this in code comments or a separate schema definition.
• Add error handling with recovery guidance: catch HTTP errors and return 'Failed to create note: {status}. Verify API_URL is correct and Feishu service is accessible. Retry in 30 seconds.' Distinguish retryable (5xx, timeout) from user-fixable (4xx, invalid input) errors.
• Validate API_URL format on server startup and per-request. Reject malformed URLs early with clear error: 'Invalid API_URL: must be a valid Feishu webhook URL (https://...)'. Add timeout (5s) to fetch() call to prevent agent hangs.