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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses the auth requirement (Authorization: Bearer sk_...), the two authorization modes, and the settlement-dependent nature of the response (transaction and rows appear once the batch is settled).

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?

Sized reasonably for the information it carries, but it is structured as one long run-on sentence with two parallel colon-lists, making it hard to parse. The keyed-vs-public distinction is buried rather than front-loaded.

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 no output schema present, the description usefully compensates by enumerating what the response contains (usage line, payment, settlement, proof URL) and covers both authenticated and public access. It is nearly complete for a one-parameter read tool, lacking only explicit routing to sibling tools.

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% and the single required parameter is already documented in the schema, so the baseline is 3. The description adds marginal meaning by tying the id to the endpoint template GET /x402/v1/receipts/{id} ('any request id'), but provides no extra format or sourcing detail.

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 the specific resource (a request's receipt) and enumerates its contents (usage, price sheet version, cost, settlement, transaction, onchain digest), and it distinguishes two modes: keyed vs public receipt. It is clearly more than a restatement of the name, though it never uses a plain verb and leans on heavy jargon.

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 implies usage conditions - provide the calling key for your own request's receipt, or omit it to fetch the public receipt of any request id including x402 ones. That conditional is useful, but there is no explicit when-to-use-this-vs-alternatives guidance referencing siblings such as x402_pay or quote.

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