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

With readOnlyHint/idempotentHint/destructiveHint already declaring the safety profile, the description goes well beyond them: exact price, free-refusal behavior on coverage gaps, per-IP rate limiting shared with other tools, x402 payment path, api_key metering for invoicing, and the Ed25519 receipt's limits (not a certified extract, not legal advice). This is the kind of behavioral context an agent needs and cannot get from 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?

Front-loading the price and the core deliverable is good, but the description is dense and rambling, embedding a receipt disclaimer and a certified-extract SKU note (explicitly not an MCP tool) that do not help an agent select or invoke this tool. Several clauses could be cut without losing selection signal.

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?

An output schema exists, so return values need not be explained, and the description still covers cost, refusal semantics, rate limits, payment paths, and receipt behavior. The only real gap is the unaddressed boundary against closely related siblings, which the usage dimension already penalizes.

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 coverage is 100%, so every parameter is already documented in the schema, which sets the baseline at 3. The description restates a few parameter effects (income tax on taxable_income, first working day from start_date, receipt default false) but adds little beyond the schema text, and it even mentions NG/KE PAYE while the country enum permits only 'ae'.

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 and deliverable: cost a hire by returning a cited dossier with a wage-floor verdict, employer/employee contributions, employer cost, and optional income tax. It is clearly distinguishable from generic siblings like compute_employment_cost or check_minimum_wage, though it never explicitly says how it differs from them. Naming the covered country (AE) further narrows the scope.

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 gives operational context (paid at $0.50, free refusal on coverage_gap, shares the 3 free calls/IP/day, pass api_key or get an x402 requirement), which implies when the call is viable. However, it never states when to choose this over siblings like compute_employment_cost, hire_compare, or check_minimum_wage, leaving the main routing decision to inference.

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