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

With no annotations, the description carries the burden of transparency, and it does disclose the tool's outputs (monthly payment, total interest, payoff, optional full schedule). However, it omits behavioral details such as how extra payments affect results, rounding rules, or handling of invalid inputs. The optional schedule is mentioned, which is a useful behavioral hint.

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 a single, front-loaded sentence that efficiently conveys the core purpose and outputs. There is no filler, but it is so brief that it sacrifices informative detail for brevity.

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 tool with 6 parameters, no output schema, and no annotations, the description is too minimal. It fails to explain the purpose of two parameters (extra_payment, currency) and does not describe the schedule format or edge cases. This leaves significant gaps for an agent to invoke the tool correctly.

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 0%, and the description does not compensate by explaining the parameters. It mentions outputs that map to principal, rate, and term, but entirely misses 'extra_payment' and 'currency', leaving their roles ambiguous. The agent cannot infer their meaning from the description.

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 uses a specific verb 'COMPUTE' with a clear resource 'level-payment loan' and lists concrete outputs (monthly payment, total interest, payoff, schedule). This distinguishes it from sibling tools like calc_irr or calc_npv, which handle different financial calculations.

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 implies use for standard amortization loans with level payments, giving some context. However, it does not explicitly state when to use this tool over alternatives, nor does it mention exclusions like adjustable-rate loans or non-standard payment schedules.

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