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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds useful context beyond that: the 52-week assumption, gross-before-tax amounts, and the fact that 'to_salary' resolves to annual, monthly, and weekly pay figures. It does not contradict the annotations.

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?

Three compact sentences deliver the purpose, both modes, the calculation basis, and the currency/tax context. The most identifying information is front-loaded, and the source URL is a minor but legitimate addition.

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 conversion tool with read-only annotations, 100% parameter schema coverage, and an existing output schema, the description is complete. An agent can correctly select the tool, choose a mode, and supply the right parameters without missing information.

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% and every parameter already has a meaningful description. The tool description reinforces the mode-parameter pairing and the gross GBP context, but it does not add materially new semantic detail beyond what the schema already provides.

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 states a specific verb ('Convert'), a clear resource (hourly pay rate ↔ annual salary), and explicitly names the two modes and their outputs. It is distinct from the general 'calculator' cohort, though it does not name any specific sibling alternative such as pro_rata_salary_calculator.

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 mode descriptions make the intended use clear: use 'to_salary' when starting from an hourly rate and 'to_hourly' when starting from a salary. However, there is no explicit when-not-to-use guidance or mention of related salary tools like take_home_pay_calculator or pro_rata_salary_calculator, leaving the agent to infer boundaries.

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