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

Goes well past the annotations (readOnly/idempotent/openWorld) by disclosing pricing, the free-refusal contract, rate-limit sharing, the x402 payment fallback when no api_key is passed, and receipt issuance behavior on paid success only. These are exactly the operational traits an agent needs before invoking a paid endpoint.

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-loads the price and core purpose in the first clause, then layers payment, refusal, and receipt details. It is dense but each sentence carries distinct information, with minor waste from repeating the certified-extract caveat in both the description and the receipt parameter.

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 an output schema present and full parameter/annotation coverage, the description completes the picture by covering payment mechanics, refusal semantics, quota sharing, and receipt verification routing. Nothing material 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 baseline is 3. The description mostly restates schema semantics ('income tax on taxable_income', 'first working day on or after start_date', receipt default false) rather than adding new per-parameter meaning beyond what the schema already documents.

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?

States a specific verb and resource plus the full deliverable set: 'Cost this hire: one cited dossier for a salary - wage-floor verdict, employer and employee contributions..., employer cost, optional income tax...'. It also scopes the geography ('Countries here: MX'). It stops short of naming the nearest siblings (compute_employment_cost, compute_income_tax, check_minimum_wage) that it apparently bundles, so differentiation is inferential rather than explicit.

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?

Gives clear conditions: it is a paid tool ('PAID ($0.50)'), only MX is covered, incomplete answers are refused free with coverage_gap/no_charge, and api_key vs x402 is spelled out. It also notes the 3-free-calls-per-IP quota is shared with the answer tools. No explicit when-not-to-use guidance against the sibling compute_* tools, which is the only gap.

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