credit_card_payoff

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

With no annotations, the description carries the full burden, and it largely does: it discloses the computed outputs (months, total interest, difference), the returned artifacts (formula in words, pre-filled calculator link), and scopes the tool as education-only. It does not cover edge cases such as a payment too small to ever clear the balance, so it falls short of a 5.

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 dense sentence that front-loads the core computation before the optional payment comparison and the return artifact. No filler, though the parenthetical '(optional)' and trailing caveats make it slightly heavy for one sentence.

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?

No output schema exists, but the description compensates by naming what is returned (formula in words and a calculator link), and the educational framing covers the tool's purpose. It is nearly complete; only the non-terminating-payment edge case and unit defaults for min_pct/min_floor are left implicit.

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 description coverage is 100% across all 6 parameters, so the schema already documents APR, balance, min_pct, payment, min_floor, and min_plus_interest semantics. The description only restates the minimum-payment vs fixed-payment comparison in prose, adding no syntax or format detail beyond the schema, so the baseline 3 is appropriate.

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?

States a specific verb+resource (credit card payoff computation) and enumerates exactly what it computes: months and total interest under a minimum-only scenario, a fixed-payment scenario, and the difference. This is clearly distinguishable from siblings like debt_consolidation or loan_cost_by_term.

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?

Implies usage via 'Education only' and the payoff context, but never states when to pick this tool over debt_consolidation or loan_cost_by_term, nor any prerequisites. The scope is inferable but no explicit routing guidance is given.

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