report_purchase

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

Annotations only declare readOnly=false, idempotent=false, destructive=false. The description goes well beyond: authentication via a signed key, an on-chain verification that the tx paid that seller within 7 days, the one-report-per-payment uniqueness rule, and the downstream effect that deliveries raise Trust Score while failures trigger an immediate recheck.

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?

Front-loaded with the trigger condition, then parameters, then server-side behavior, then return value. Telegraphic but every clause carries information; nothing is redundant.

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?

Covers the full lifecycle an agent needs for a six-parameter mutation: when to call, what to pass, what the server verifies, what effect the call has, and that an output schema exists (so return values need no elaboration).

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%, so the baseline is 3; the description still adds workflow meaning by tying tx to the PAYMENT-RESPONSE header and clarifying that preflight_id and result_sha256 are optional correlates of the payment. It does not add format or validation detail beyond what the schema already documents.

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?

States a specific verb and resource (report a purchase) plus the exact trigger context: immediately after paying an x402 endpoint on Base or Solana. An agent can tell instantly that this logs payment outcomes to the seller's reputation, which no sibling tool does.

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?

Gives explicit timing ('use right after you paid'), names the sibling-adjacent artifacts to carry over (PAYMENT-RESPONSE header for tx, preflight_id from a prior preflight event), and states a hard constraint: one report per payment. The valid outcome vocabulary is enumerated inline.

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