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

The description adds substantial behavior beyond the annotations, including the $0.05 USDC per-call price, x402 payment inside the call, and the fact that failed calls are not charged. It also describes the external fetch/check/sign mechanics and the contents of the attestation.

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 definition is front-loaded with the purpose and then proceeds to mechanism, buyer verification, price, and failure policy without irrelevant material. The sentences are dense but each carries useful information for invoking or evaluating the tool.

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 external verification tool, the description covers the important mechanics, cost, and failure behavior. It does not explicitly state what the tool call returns to the caller, but the public verification URL and signed attestation concept make the outcome largely inferable.

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 both parameters are already documented. The description reinforces their roles, but it mostly repeats the same-host and sample/paid-route relationship rather than adding syntax or edge-case semantics beyond the schema.

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 operation and resource: a signed attestation of an API's sample output, intended as a trust proof for an x402 seller. It is clear what the tool produces, but it does not explicitly distinguish itself from sibling tools such as rank_sample or lint_listing.

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 target scenario is implied clearly enough: an x402 seller wants a trust proof before buyers pay. However, the description gives no explicit when-to-use/when-not-to-use guidance and does not name sibling alternatives that an agent should consider instead.

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