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

Beyond the annotations it discloses the price, currency, chains, the payment protocol and endpoint, and the idempotency contract (a replayed key returns the original receipt and the first request wins even with different inputs). That is exactly the kind of cost/side-effect/failure-mode context annotations cannot express, and nothing conflicts with readOnlyHint=false or idempotentHint=true.

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 scoping rule and the endpoint are front-loaded and every clause carries information (scope, payment, price, URL). The 'Skip the sweep' opener is promotional filler and the payment details are packed into a single dense run-on, but overall it is tight for the amount of operational detail conveyed.

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, return-value description is unnecessary, and the description covers the two things an agent most needs and cannot infer: how to pay and how idempotency behaves. What remains unstated — what 'signed receipt' verification should look like or how the ranking is ordered — is partially recoverable from the schema and output shape, so nothing essential 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 all three parameters are already documented in detail, including the surface slug examples, the UUID v4 idempotency rules, and the include_unverified default. The description only restates the 'omit surface = full directory' rule already in the schema, adding negligible new meaning — baseline 3.

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 names a concrete resource — a ranked directory of ranking surfaces covering methods, integrity, freshness and the provider's own standing — delivered as a signed receipt, which is far from a tautology of the name. It is slightly obscured by marketing framing ('Skip the sweep') and by never stating the operation as a plain verb, but an agent can still tell it returns a directory entry set rather than a trust check or attestation like the sibling tools.

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 explicit operating context: omit `surface` for the full directory, and payment is required via POST to paid_url with an x402 v2 PAYMENT-SIGNATURE header at $0.25 USDC. It does not contrast with any sibling (e.g. trust_report or diligence_pack), but none of the listed siblings appears to be a direct substitute for a paid ranking directory, so the missing exclusion is a minor gap.

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