Single tool 'add_plus_and_ten' has critical definition gaps. Tool name violates verb_noun convention and is misleading, it suggests adding two numbers plus 10, but the description (in Japanese) is unclear without translation. Input schema present with basic types but lacks proper descriptions for parameters 'a' and 'b'. No output schema documented. Description is non-English and too brief (12 chars in English: 'Add numbers'). No error handling guidance. Tool appears to be a demo/test implementation rather than production-grade.

• Rename tool to 'add_numbers' or 'sum_values' to follow verb_noun convention and clarify intent.
• Replace Japanese description with English: 'Adds two numbers and returns their sum plus 10. Use this to perform arithmetic operations.' (50 - 100 chars).
• Add parameter descriptions: a='First number (integer or float)', b='Second number (integer or float)'.
• Document output schema: {type: 'object', properties: {result: {type: 'number', description: 'Sum of a + b + 10'}}}.
• Add error handling: validate inputs are numbers; return 'Invalid input: a and b must be numbers' if validation fails.