Server has 2 tools with reasonable naming and descriptions, but significant gaps in parameter descriptions, output schema documentation, and error handling. Names follow verb_noun convention (request_otp, verify_otp) which is good. Input schemas are present with type declarations, but lack granular descriptions for each parameter. Output schemas are not documented. Error handling guidance is missing. The server is a Phoenix HTTP service for OTP authentication, functionally sound but needs polish for production agent use.

• Document output schemas for both tools. Example: 'request_otp returns {request_id: string, expires_in_seconds: number}' and 'verify_otp returns {success: boolean, user: {id: string, phone_number: string, created_at: string}} or error: {code: string, message: string}'.
• Add minLength, maxLength, and pattern constraints to the input schema for phone_number (e.g., pattern: '^\+?[0-9]{1,15}$') and code (minLength: 6, maxLength: 6, pattern: '^[0-9]{6}$').
• Enrich parameter descriptions with validation rules and examples: 'phone_number (string, 1-15 digits, optional + prefix; e.g., +14155552671)' and 'code (string, exactly 6 numeric digits; e.g., 123456)'.
• Add error recovery guidance to tool descriptions. E.g., 'If verify_otp returns code_invalid, the user should request a new OTP via request_otp. If code_expired, same recovery. If too_many_attempts, user must wait before retrying.'
• Explicitly document side effects in request_otp description: 'Creates a new user record if the phone number is not yet registered. Subsequent calls with the same phone number reuse the existing user.'
• Consider adding tool annotations (idempotentHint=false for request_otp, readOnlyHint=true for verify_otp) to the tool definitions to help agents understand retry safety.