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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safe-read profile is covered. The description usefully adds that the credential changes the scope of the result, that settlement fields appear only 'once settled' (eventual availability), and names the backing endpoint GET /x402/v1/receipts/{id}; it says nothing about error behavior or rate limits.

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 mode distinction is front-loaded, which is good, but the second half is a comma-spliced pile-up of nouns ('the usage, the price sheet version, the cost and, once settled, the settlement, its transaction and the rows behind the onchain digest') that is hard to parse in one pass.

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?

There is no output schema, so the description carries the burden of explaining what comes back, and it enumerates the returned fields for both modes plus the endpoint. For a single-parameter read tool this is close to complete, with only error/empty-settlement handling left implicit.

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?

With one parameter and 100% schema description coverage, the schema already explains that request_id is the id returned with the completion (and the x-request-id header). The description only echoes 'request id' and the endpoint path, adding no format or constraint detail 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 resource (a request's receipt) and enumerates its contents: usage, price sheet version, cost, settlement, transaction, and onchain digest rows. It clearly distinguishes two retrieval modes (own request via API key vs. public receipt of any id), though it never names a sibling to contrast with.

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 conditions for the two modes: 'With the API key that made the request' versus 'With no key: the public receipt of any request id, x402 ones included.' This tells the agent which invocation applies, but offers no guidance against alternatives such as balance or quote.

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