Two tools with basic schemas and minimal descriptions. Both tools have input schemas with proper types (number, enum), but descriptions are extremely short (10-40 chars), falling well below the 50-200 char baseline for LLM-optimized descriptions. No output schema documentation. Error handling is minimal (only divide-by-zero check in 'calculate'). Tool names lack action verbs ('add' and 'calculate' are weak; 'perform_addition' and 'perform_calculation' would be clearer). No parameter descriptions beyond type hints. No guidance on when to use one tool vs. the other.

• Expand tool descriptions to 50-200 chars. Example for 'add': 'Adds two numbers and returns their sum. Use this for simple arithmetic when you need to combine two numeric values.'
• Add descriptions to all parameters. Example: 'a: The first number to add (any real number)' and 'b: The second number to add (any real number)'.
• Document output schema explicitly. Specify that both tools return a single numeric result as a text string, or restructure to return {result: number, operation: string}.
• Rename tools with clearer verbs: 'sum_numbers' instead of 'add', 'perform_arithmetic' instead of 'calculate'. This helps LLMs disambiguate intent.
• Add input validation and error messages. For 'add', validate that inputs are numbers; for 'calculate', validate operation enum and provide actionable error text like 'Invalid operation: must be one of: add, subtract, multiply, divide'.