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

Annotations already declare a non-read-only, idempotent, non-destructive, open-world write. The description adds substantial behavior beyond that: no API key required, on-chain verification that the tx paid a known payTo in USDC/USDT within 7 days, signature into a public log, and downstream effects on Trust Score plus an immediate recheck on failure. Minor gap: it doesn't state what a rejected or duplicate report returns, though an output schema exists.

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 core instruction and its prerequisites are front-loaded in the first sentence, followed by verification mechanics and consequences in a compact block. The closing line ('This is how agents learn which sellers deliver.') is motivational filler rather than operational guidance.

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 six-parameter write tool with annotations and an output schema, the description covers the prerequisites (post-payment, no key), the verification rules (known payTo, USDC/USDT, 7-day window), the cardinality constraint (one report per payment), and the consequences of reporting — nothing an agent needs in order to call it correctly 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 coverage is 100%, so the schema already documents all six fields, and the description only reinforces the tx field mapping (PAYMENT-RESPONSE transaction) already stated in the schema. It adds the useful 7-day verification-window constraint but says nothing about preflight_id or result_sha256, so the baseline of 3 applies.

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 specific verb (report) and resource (payment outcome for an x402 endpoint) and enumerates the allowed outcomes, so the agent knows exactly what action is performed. It also implicitly separates itself from preflight_payment and check_service by scoping the call to 'after you paid'.

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?

Timing guidance is explicit and actionable: call this only 'after you paid an x402 endpoint on Base or Solana', and 'one report per payment'. It does not explicitly name sibling alternatives such as preflight_payment for the pre-payment case, leaving the before/after split partly implicit.

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