Single tool with explicit registration but significant gaps in descriptions and parameter documentation. Tool name follows verb-noun convention (create-user), which is good, but parameter descriptions are completely missing (null values in schema). Input schema is present with types defined. Output is unstructured text rather than documented schema. Tool annotations are present but descriptions lack context about prerequisites, return structure, and error cases. No parameter validation hints provided.

• Add non-empty descriptions to 'name' and 'email' parameters. Example: 'name: Full name of the user (2-100 characters, alphanumeric + spaces only)' and 'email: Valid email address in format [email protected]'
• Expand tool description from 18 to 80-150 characters to include: What it does, when to use it, what it returns, and error cases. Example: 'Create a new user account with name and email. Returns the new user ID. Email must be unique; will fail if email already exists. Use search_users() first to check availability.'
• Document the output schema explicitly: { type: 'object', properties: { user_id: { type: 'number', description: 'The newly created user ID' }, message: { type: 'string' } }, required: ['user_id'] }
• Add email format validation hint to the email parameter description: 'Valid email format (RFC 5322 standard, e.g. [email protected])'
• Improve error messages to be actionable. Instead of 'Error: Failed to create user', return specific errors: 'Email already exists' or 'Invalid email format' so LLM can self-correct
• Update tool description to state: 'This tool writes to persistent storage. Each call creates a new user and increments the user ID counter. Not idempotent, calling twice with the same name/email creates two records.'
• Add a validation mechanism or dry-run capability before actually writing user data, especially for destructive operations