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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable context by noting the amounts are gross in GBP before tax, and that output includes yearly, monthly, and weekly figures, which is beyond the annotations. It does not contradict any annotation.

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, well-structured paragraph that front-loads the core purpose and immediately follows with the two modes and key defaults. It is concise, with no wasted words, and every sentence contributes to understanding how to use the tool.

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?

The tool is a simple calculator with clear schema and annotations. The description covers the essential operational aspects: purpose, modes, default working days, output types, currency, and tax treatment. Since an output schema exists, return values are already specified elsewhere. Nothing critical for an agent to call it correctly is missing.

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 every parameter (mode, salary, dayRate, workingDays) is documented in the schema. The description adds value by explaining the default workingDays (220) and the nature of the output (yearly, monthly, weekly figures), which is not in the schema. This enriches the meaning of the parameters beyond the schema definitions.

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 clearly states the tool converts between a contractor day rate and annual salary equivalent, specifying the two modes ('to_salary' and 'to_rate') and the default working days (220). It is distinct from sibling calculators by focusing on day rate vs salary conversion, and the verb 'convert' plus resource 'day rate and annual salary' makes the purpose unambiguous.

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 explains the two modes and what each does ('to_salary' turns a day rate into yearly, monthly, and weekly figures; 'to_rate' turns a salary into a day rate). This gives clear guidance on when to use each mode. It does not explicitly mention alternatives like hourly_to_salary or pro_rata_salary_calculator, but the tool's specific scope is evident from the name and description, so a 4 is appropriate.

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