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

With no annotations, the description carries the full behavioral burden, and it does so thoroughly: it discloses the $0.10 paid cost, the unknown-not-zero refused-list behavior, the fact that income tax is excluded, the api_key/x402 payment mechanism, receipt semantics, and the caveat that receipt is neither a certified extract nor legal advice.

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 description is dense but well ordered: paid status and core behavior come first, followed by the tax exclusion, payment options, and receipt details. Some redundancy exists with the receipt parameter schema, and the parenthetical about the certified extract is long, but every sentence contributes operational 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 paid, complex tool with 12 parameters and no output schema, the description is unusually complete: it describes the output format, payment/auth path, edge cases (refused list), limitations (no income tax, not legal advice), and verification pathway via verify_answer_receipt. An agent has enough context to select and invoke it correctly.

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 baseline is 3 and the schema already documents every parameter including enums and defaults. The description adds useful payment and receipt context, but it does not add material per-parameter semantics beyond what the schema 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 leads with a specific verb and resource: 'Cost to employ: prices every statutory contribution on both the employee and employer sides for a gross salary.' It also states the exact output shape (line-by-line amounts, instrument citations, explicit refused list) and explicitly distinguishes itself from income-tax computation, making it easy for an agent to separate from siblings like compute_income_tax.

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 clearly states what the tool does and does not do, and explicitly routes income-tax/gross-to-net requests to compute_payroll where supported. It also explains the payment path (api_key vs x402). It slightly weakens routing by naming compute_payroll, which is not among the provided sibling tools, and does not address when to prefer check_minimum_wage or compute_vat.

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