Single tool 'add' has critical definition gaps. Tool name lacks action verb (should be 'compute_sum' or 'add_numbers'). No tool description provided. Input schema uses Zod but lacks explicit type/description metadata visible in source. Output schema not documented. No error handling guidance. Fails multiple hard scoring rules.

• Rename tool from 'add' to 'compute_sum' or 'add_numbers' to follow verb_noun convention and clarify intent.
• Add a tool description (50 - 200 chars): 'Adds two numbers and returns their sum. Use this for arithmetic calculations.'
• Add descriptions to parameters: a: 'First number to add (numeric value)', b: 'Second number to add (numeric value)'
• Document the output schema in code comments or JSDoc: 'Returns {content: [{type: "text", text: string}]} where text is the sum as a string.'
• Add input validation and return structured error messages: 'Invalid input: a and b must be numbers. Got a={typeof a}, b={typeof b}.'