credit_card_payoff

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Lacks disclosure of assumptions (e.g., compounding frequency, monthly payment priority when both min_payment and monthly are given), no mention of read-only nature (though inferred), and no limits or side effects described.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Concise with a single sentence of purpose and a clear parameter list, though the structure is minimal and could be improved with grouping or formatting.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description still fails to explain the calculation logic (timeline unit, interest savings method), making it incomplete for an agent to fully understand the tool's behavior.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Explains each parameter with example for rate, but does not clarify the interaction between optional parameters (min_payment and monthly) or their defaults, leaving ambiguity for the agent.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states it calculates 'credit card payoff timeline with interest savings,' which is specific and distinguishes from generic loan calculators among siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like loan_calculator or amortization_calc, nor any prerequisites or context for use.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.