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

With no annotations, the description carries the full behavioral burden and does so thoroughly. It discloses that the signature is an HMAC under a key only XRPLHub holds, that the result is XRPLHub's own attestation not independently verifiable proof, that the buyer need not control the wallet, that the first call returns a payment request valid 90 days, and that the second call returns certId and verifyUrl.

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 description is dense but every sentence earns its place: purpose, trust model, call flow, parameters, and auth requirement. It is front-loaded with the primary purpose and proceeds logically through caveats and sequencing. The parameter sentence is compact and does not bloat the text.

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 two-step, paid credential tool with no output schema, the description fully explains the sequence, return values (payment request, then certId/verifyUrl), fee (1 XRP or 1 RLUSD), validity period, trust model, and the fact that no signup is required. Missing edge cases like invalid wallet or expired uuid are minor against this level of completeness.

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% and the description reinforces roles by noting wallet_address format ('r...'), currency default, and uuid for the second call only. It adds the explicit constraint that the second call must reuse the same wallet_address together with the returned uuid, which goes beyond the schema's individual parameter descriptions.

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 opens with a specific action and resource: 'Get a certificate of a wallet's XRPLScore, signed by XRPLHub, with the score computed fresh at issuance.' This clearly distinguishes the tool from siblings like check_xrpl_score (score checking) and verify_attestation (verification) by focusing on issuance of a paid, signed credential.

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 description provides a clear usage context: a two-call flow, payment amount and validity, parameter roles, and 'No signup.' It even hints at when not to use the tool for verification ('counterparty checks it by asking XRPLHub's verify URL'). However, it does not explicitly name sibling alternatives or state exclusion conditions, so it stops short of full when/when-not guidance.

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