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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses a key limitation ('tax cost of filing separately is not modelled'), states that the answer explicitly acknowledges that limitation, and describes what results are produced. This is strong transparency for a comparison 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?

The description is two tight sentences. The first states the operation and expected outputs; the second adds the critical scope limitation. There is no filler or repetition of schema information.

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 medium complexity and lack of an output schema, the description gives enough about the scenario, the deliverable, and the modeling limitation. It could say more about how borrower/spouse AGI are combined or what 'swing' means numerically, but the schema and clear framing cover most agent needs.

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%, so the schema already documents all six parameters clearly. The description adds the conceptual framing ('same federal loan book' and 'best income-driven plan') but does not add syntax, formats, or behavioral detail beyond the schema. 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?

The description names a specific verb ('Run'), a concrete resource ('federal loan book'), and the exact comparison being made ('filing jointly and filing separately'). It also specifies the output ('swing in the best income-driven plan's payment and lifetime cost'), which clearly differentiates it from siblings that compare repayment plans rather than filing statuses.

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 intended use case is explicit: same loan book run under both filing statuses to see the swing. The LOAN SIDE ONLY warning also tells the agent when not to use this tool, i.e., when tax consequences of filing separately must be modeled.

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