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

Annotations already cover the safety profile (readOnly, idempotent, openWorld), yet the description adds substantive context beyond them: verification happens 'at final finality', the vault code hash is read at the same block, and the call costs $0.005 USDC via x402. Pricing and finality semantics are exactly the kind of behavior an agent cannot infer from annotations.

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 check is front-loaded in the first clause and the parenthetical reason list packs the failure modes into one sentence. The pricing sentence is separate and earns its place, though the main sentence is dense enough to be slightly hard to parse on a first read.

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 entire return-value burden — and it does, specifying 'valid' versus the specific rejection reasons plus the returned vault code hash. With 8 parameters at full schema coverage, nothing essential about calling or interpreting this tool 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 description coverage is 100%, so the baseline is 3, but the description adds meaning: minAmount is framed as a floor ('at least a given amount') rather than an exact match, and the receipt is 'bound to the seller request hash', clarifying the role of requestHash. It does not mention the nonce alternative to requestHash, so it falls short of a 5.

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 — a seller-side verification that an Allowance vault receipt on NEAR paid an account at least a given amount — plus the binding to the seller request hash and final finality. None of the siblings (risk, screening, listing, enrichment) overlap with receipt verification, so the scope is unambiguous.

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?

'Seller-side check' establishes the caller context clearly, and the enumerated failure reasons (not paid yet, wrong payee, amount, asset or request, unknown receipt, not a vault) implicitly tell the agent what conditions it is testing. It does not name alternatives or state when NOT to use it, which keeps it short of a 5.

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