mortgage_calculator

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

No annotations are provided, so the description carries the full burden of disclosing behavioral traits. It only states the basic computation but fails to mention critical details such as assumptions (e.g., fixed vs. adjustable rate, compounding frequency), whether taxes/insurance are included, or the nature of the amortization output. This leaves significant ambiguity for an agent.

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?

The description is highly concise: a single sentence followed by a parameter list. Every element is functional and there is no extraneous text. The structure is clear and easy to scan, making it efficient for an agent to parse.

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?

Given the existence of an output schema, the description need not detail return values, but it should provide enough context for parameter usage and behavioral expectations. The description covers the purpose but lacks guidance on input validation, edge cases, or assumptions. For a simple calculator with three parameters, this is adequate but not thorough.

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?

Schema coverage is 0%, so the description must compensate. It adds a useful example for the rate parameter (e.g., 5.5 for 5.5%) but offers no further clarification for principal or years. While the example helps, the description does not fully explain the expected units or constraints for all parameters, achieving only marginal added value.

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?

The description clearly states the tool calculates monthly mortgage payments, total interest, and amortization. It uses a specific verb ('calculate') and resource ('mortgage payments'), and distinguishes it from siblings like loan_calculator or auto_loan_calc by explicitly mentioning amortization, which is characteristic of mortgage calculators.

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?

The description provides no guidance on when to use this tool versus alternatives. Given the many sibling financial calculators (e.g., loan_calculator, rent_vs_buy_calc), explicit when-to-use or when-not-to-use information is missing, making it likely for an agent to misuse or overlook this tool.

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