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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile needs no restating. The description adds real context the annotations cannot: the default assumptions (40 hours/week, 52 paid weeks, a 2,080-hour year) and that results are gross pre-tax. It stops short of warning that changing hours_per_week or paid_weeks_per_year makes all figures assumptions rather than facts, but the coverage is solid.

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?

Front-loaded with the conversion scope, then examples, then the assumptions, then the sibling routing – a sensible order with no filler. The example questions are slightly redundant with the first sentence and could be shortened, keeping it just under a 5.

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?

An output schema exists, so return formatting is out of scope for the description. Given five parameters with enum and defaults, the description supplies exactly what is missing: default assumption semantics, gross-vs-net boundary, and tool choice. Nothing an agent needs to invoke it correctly is absent.

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 the baseline is 3; the description earns above that by explaining the combined effect of hours_per_week and paid_weeks_per_year ('a 2,080-hour year is the default') rather than merely restating each field. days_per_week, the least intuitive parameter, is still only defined in the schema and not touched on in prose.

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 and resource ('Convert pay between hourly, daily, weekly, biweekly, semimonthly, monthly and yearly, in either direction, from one amount') and anchors it with two concrete example questions. This is unmistakably distinct from the sibling payroll tools such as overtime_pay or us_paycheck_take_home.

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?

Explicitly routes the agent: 'Use us_paycheck_take_home for take-home pay after tax and overtime_pay for pay that includes overtime hours.' It names the alternatives and the condition that selects them, and the 'gross, before tax' clause makes the exclusion boundary clear.

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