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

With no annotations, the description carries the full burden and does substantial work: it discloses the 0.02 USDC x402 charge on Base, zero retention/ephemeral handling, and precise failure semantics (isError, payment-error.status_code, 503 admission unavailable, 409 uncertain outcome not to be retried). The remaining weakness is that 'zero-refusal' and 'lightning-fast' are unverifiable marketing claims rather than behavioral facts.

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-loads the purpose, which is good, but the opening clause is padded with 'Zero-refusal, lightning-fast' and the payment/error sentence is a dense run-on packing four distinct conditions. The information earns its place; the packaging does not.

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 paid, stateless audit tool with no output schema, the description covers cost, payment mechanics, retention, and error handling well. It stops short of describing what a successful audit response contains, which an agent needs in order to consume the result.

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 prompt, payer_address, and system_prompt are already documented, and the description largely restates payer_address. It does add meaning beyond the schema by describing redemption fields (invoice_id, signature, tx_hash, method=points) that do not appear in the input schema at all, which is genuinely useful but sits outside the declared parameters.

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: audits smart contract and code for honeypots, backdoors, reentrancy, and transfer-tax traps. That is concrete enough to separate it from a token-safety checker, but it never names a sibling or states the boundary explicitly, so differentiation is left to inference.

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 operational instructions (supply payer_address, pass invoice_id/signature in _meta.x402/payment, use tx_hash or method=points) but never says when to choose this over check_base_token_safety or deep_protocol_reasoning. Usage is implied by the audit framing rather than stated as a selection rule.

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