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

With no annotations, the description carries the burden of behavioral disclosure. It does disclose useful behavior: missing inputs fall back to documented defaults, and it outlines the calculation outputs. It does not state whether the tool is side-effect free or describe error/validation behavior, leaving some behavioral uncertainty for a pure calculator.

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?

Two sentences with no filler; the action is front-loaded and the output list is compact. The semicolon-separated list is slightly dense but every element contributes useful 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?

For a calculation tool with fully described optional parameters and no output schema, the description names the key computed outputs and the default-fallback behavior, which is enough to invoke it. It does not specify the exact response shape or calculation rules for statutory leave beyond the 12.07% formula, but the schema covers input expectations.

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 7 parameters. The description only adds a general 'missing inputs fall back to defaults' note and references hours worked and bank holidays; it does not add material meaning beyond the parameter descriptions.

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 identifies the resource (Statutory leave tracker calculator) and the action (Run), and enumerates what it computes: statutory leave, accrued hours at 12.07%, bank-holiday fill, and remaining days. It does not explicitly contrast with sibling calculator_describe, but the intended calculation role is unmistakable.

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 instruction to run the calculator implies use when a statutory-leave calculation is needed, and the mention of defaults gives practical context. However, it never states when not to use it or points to alternatives such as calculator_describe, so the guidance is only implicit.

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