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

Annotations already indicate readOnlyHint, idempotentHint, and destructiveHint=false. The description adds the statutory cap, the 5.6-week calculation rule, optional scaling, and return units (days/weeks), providing meaningful behavioral context beyond the annotations. No contradiction.

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 sentences: core purpose front-loaded, optional scaling in the second sentence, output/source in the third. Every sentence is informative and there is no filler.

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 two-parameter calculator with an output schema and non-destructive annotations, the description covers the calculation rule, the statutory cap, optional month scaling, and return units. Nothing essential for correct invocation 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 the schema already documents both parameters. The description restates the roles of daysPerWeek and months but adds little beyond the schema; the part-year scaling phrasing mirrors the schema's default of 12 months.

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 ('work out'), a precise resource ('UK statutory paid holiday entitlement'), and the calculation basis (5.6 weeks a year capped at 28 days). This clearly differentiates it from sibling tools like hopi_working_days_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 description provides clear context for when to use the tool (UK statutory holiday calculation) and the optional part-year scaling via months. It does not explicitly name alternatives or exclusion conditions, but no sibling tool directly overlaps in function.

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