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

Adds real behavioral context beyond the readOnlyHint annotation: it discloses what is returned (valid, signer, x402-signer status), when the request-matching check applies (with route and input), that a changed verdict/receipt fails, and that nothing is stored. This is useful, non-redundant disclosure.

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 key point ('Free: check ...') but then runs into a long parenthetical enumeration and multiple clauses in one paragraph. It is dense and mostly earns its place, but could be tightened.

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?

Given an output schema and full schema coverage, the description need not explain return values, yet it does summarize them and covers failure semantics and storage behavior. Adequate and nearly complete for this tool's complexity.

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 the baseline is 3, but the description adds functional meaning: response is the whole answer, and route+input enable an exact-request match. That clarifies the intent of the optional parameters beyond their schema text.

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 (check/verify) and resource (the signed receipt carried by every paid x402 Doctor answer), and enumerates which answer types it covers. It is clear what the tool does, though it does not explicitly distinguish itself from the sibling check_payment_proof, which could overlap.

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 a concrete motivating scenario ('to prove later which verdict you got before paying an endpoint') and notes the equivalent HTTP route. There are no explicit when-not conditions or named alternatives, so it stops short of a 5.

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