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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuine context about the rules applied (clear days, the 5-day rule, court office closures) but says nothing about the return shape, rounding conventions or edge cases 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?

The purpose and rule coverage are front-loaded in the first clause, followed by the usage note on presets. It is dense but every clause corresponds to real functionality; slight bloat from listing CPR citation numbers alongside each concept.

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?

With no output schema, the description carries the burden of indicating what comes back, and it only loosely implies a computed deadline date without describing the result (single date, adjusted date, explanation). For a six-parameter calculator the coverage of inputs is good but the output side is left implicit.

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 six parameters including enums and the preset list. The description restates the preset-vs-own-period choice and lists a few example presets, largely duplicating what the schema provides rather than adding new meaning. Baseline 3 applies.

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 names a specific verb (works out a deadline) and a precise resource (a CPR deadline in England and Wales), then enumerates the rules applied (CPR 2.8, 2.10, 6.26, PD 2A). It is very clear what the tool does. However it never distinguishes itself from siblings like calculate_deemed_service, which it partially overlaps by offering 'latest days to email or post a document for deemed service'.

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?

It explains how to drive the tool (use a named preset or supply your own period plus a start date) but not when to choose this over siblings such as calculate_deemed_service or calculate_detailed_assessment_deadlines. Usage is implied by the CPR scope rather than stated with conditions or exclusions.

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