Single tool 'hello_tool' has a basic description but critical gaps in schema documentation and parameter clarity. The input schema is visible in code (name: string, required) but lacks formal JSON Schema documentation in the tool definition. Description is minimal (18 chars) and does not explain when/why to use the tool or what it returns. No output schema is documented. The tool name lacks a clear action verb (should be 'greet_user' or 'send_greeting'). Error handling is minimal, the handler returns generic 'name must be a string' without recovery guidance.

• Rename tool to 'greet_user' to start with a clear action verb matching LLM expectations.
• Expand description to 50-150 chars: 'Greet a user by name and return a personalized greeting message. Use this to acknowledge users or generate welcome messages.'
• Document output schema: specify that the tool returns a plain text string containing the greeting.
• Add format constraint to 'name' parameter: 'Name of the person to greet (1-100 characters, alphanumeric and spaces only).'
• Improve error handling: return 'Invalid name format. Expected 1-100 alphanumeric characters and spaces. Got: [value]' to enable LLM self-correction.