Single tool 'add' has critical definition gaps. Input schema present (Zod: {a: number, b: number}) but parameter descriptions are null, violates the requirement that every parameter needs a description. Tool description is missing entirely (null in schema). No output schema documented. The tool is trivial (arithmetic) but fails basic quality standards: descriptions are mandatory per pattern:tool-description, and null descriptions score 0. No error handling, no recovery guidance.

• Add a tool description: 'Adds two numbers and returns their sum. Use this to perform basic arithmetic calculations.'
• Add parameter descriptions: a='First number to add (numeric)', b='Second number to add (numeric)'
• Document the output schema: {type: 'object', properties: {result: {type: 'number', description: 'The sum of a and b'}}}
• Rename tool from 'add' to 'calculate_sum' to follow verb_noun convention and improve LLM discoverability
• Add input validation and return structured error messages: 'Invalid input: a and b must be numbers. Got a={type(a)}, b={type(b)}'