Single tool 'add' with critical definition gaps. Tool description is missing entirely (null in source). No output schema documented. No error handling guidance. Naming is acceptable (verb_noun: 'add') but insufficient to overcome missing descriptions and documentation.

• Add a tool description: 'Adds two numbers and returns their sum. Use this for arithmetic calculations. Returns the result as a text string.'
• Add parameter descriptions: a: 'The first number to add (numeric value)', b: 'The second number to add (numeric value)'
• Document the output schema in the tool definition or description: 'Returns {content: [{type: "text", text: string}]} where text is the sum as a string.'
• Add input validation and error handling: check that a and b are numbers; return a clear error message if not (e.g., 'Invalid input: a and b must be numbers').
• Consider whether this tool serves a real agent use case. If this is a demo, document it as such. If production, add realistic tools (e.g., calculate_tax, compute_discount) with full descriptions and error paths.