calculate_mortgage

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

No annotations are provided, so the description carries the full burden. It mentions the return object but does not disclose behavioral traits such as whether the calculation is read-only, idempotent, or has any side effects. For a calculator tool, this is a significant gap as an agent might need to know if it modifies any data or requires authentication.

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 efficiently concise: two sentences covering purpose, return format, and a pointer to related tools. Every sentence serves a function with no wasted words.

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 (as per context), the description covers the main calculation outputs. However, it omits mention of the `with_schedule` parameter's behavior (first 12 months + last month) and does not explain that `months` is derived from `years`. Still, it is reasonably complete for a moderate-complexity tool.

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?

The input schema has 100% description coverage for all four parameters, so the schema already explains each parameter clearly. The description adds no additional parameter semantics beyond the schema, which is adequate for a baseline score of 3.

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 verb 'Calculate' and the resource 'mortgage/loan monthly payment, total cost, and optional amortization schedule'. It specifies the return fields (principal, months, monthly_payment, total_interest, total_cost). However, it does not explicitly distinguish itself from sibling tools like 'calculate_loan_payment' or 'calculate_mortgage_insurance', relying on a reference to list_bundles for related 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 minimal guidance on when to use this tool vs alternatives. The only hint is 'See list_bundles for related 'finance-france' calculators', which directs the agent to a separate tool but does not explain trade-offs or conditions for preferring this tool over similar ones like calculate_loan_payment.

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