loan_cost_by_term

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 usefully discloses that the tool returns a formula and a pre-filled calculator link and that it is education-only, but gives no detail on assumptions (e.g. amortization model), precision, or error behavior for a calculation tool.

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?

A single compact paragraph, front-loaded with the resource and outputs, and every clause earns its place (outputs, defaults, return extras, scope disclaimer).

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?

For a simple three-parameter calculation tool with full schema coverage and no output schema, the description covers outputs, defaults and scope well; only the computational assumptions behind the numbers are left unstated.

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 100%, so baseline is 3, but the description adds the default term values (36, 48, 60, 72, 84 months) that are not present in the schema for the terms parameter, genuinely extending what the agent knows.

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 names a specific resource (loan cost by term) and enumerates the concrete outputs: monthly payment, total interest, total paid. That is enough to distinguish it from siblings like credit_card_payoff or debt_consolidation, though the verb is implicit rather than stated and no sibling is named.

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?

Usage is only implied by 'Education only' and the pre-defined default terms; there is no explicit when-to-use or when-not-to-use guidance, nor a pointer to an alternative tool for other calculations.

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