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

With no annotations, the description carries the full burden and does so well: it discloses that checks are probed against the primary source and never the claimant, returns PASS/FAIL/UNVERIFIABLE with raw evidence and a reproduce command, plus an overall CONFIRMED/REFUTED/PARTIALLY_VERIFIED verdict, and defines UNVERIFIABLE as never reported as PASS. It omits operational traits like cost, auth, or rate limits, so not a 5.

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?

Purpose and the pre-payment trigger are front-loaded, and nearly every sentence adds operational detail. The main deduction is the full bilingual duplication, which doubles length without adding information for an English-reading agent.

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 zero-param, no-output-schema, no-annotation tool, the description covers the input payload, the full set of check types, and the return contract (per-check verdicts, evidence, reproduce command, overall verdict). Nothing an agent needs to invoke and interpret 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?

The schema is an empty object, so the description must compensate, and it does: it specifies the POST payload shape ({claim, checks}) and defines each check type with its assertion semantics (evm_balance asserted against expect, x402 matching live 402 challenge, x402_enforce re-request behavior, hash as sha256). This adds real meaning beyond the empty schema, though the exact field-level syntax for each check is not fully enumerated.

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 (verify) and a specific resource (the claim an agent makes about itself before you pay it), then enumerates the probe families (http, evm_balance, evm_call, evm_tx, dns, x402, x402_enforce, hash). An agent can tell this apart from generic siblings like x402-verify or x402-fact-check without opening a schema.

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 when-to-use triggers: 'Before you pay an agent', 'Use it on a stated number, a payout address, a contract ownership claim or an x402 price before you transact with that counterparty.' It does not name alternative sibling tools or state when NOT to use it, so it falls short of a full 5.

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