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

Annotations only declare readOnlyHint=true and openWorldHint=false; the description adds substantial behavioral detail: statutory redundancy pay shares the £30,000 exemption, notice pay is taxable under PENP rules, untaken holiday is not exempt, and the NI boundary differs. It also notes Northern Ireland's higher statutory limits. No contradiction with 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?

At roughly 170 words, the description is longer than average but front-loads the core purpose and uses each sentence to explain a meaningful tax nuance or regional difference. It is appropriately detailed for the complexity of the calculation and contains 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?

The description thoroughly covers the tax logic, exemptions, PENP rules, NI boundary, and Northern Ireland inclusion. However, with no output schema, it never states what the tool returns (e.g., a breakdown of tax-free amount, taxable earnings, NI, and net take-home). This is a notable gap for a 9-parameter calculator.

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?

The input schema already provides 100% description coverage with detailed explanations for all 9 parameters, so the tool description is not required to repeat them. The description adds valuable conceptual background about tax treatment and exemptions but does not elaborate on specific parameter syntax or values 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 clearly states it calculates the full redundancy package—pay, notice, and untaken holiday—and splits tax according to HMRC rules, including the NI boundary and Northern Ireland variants. It distinguishes itself from sibling tools like uk_statutory_redundancy_pay and uk_notice_pay by covering the combined package rather than a single component.

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 gives strong contextual guidance, explaining that the common belief about the £30,000 exemption is misleading and that notice and holiday are taxed as earnings. It implies when this tool is needed (when all three components must be calculated together) but does not explicitly name alternative tools or state when not to use it.

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