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

No annotations exist, so the description carries full weight. It discloses the paid x402 mechanism, the fact that the tool never broadcasts transactions, and that it returns calldata for self-execution. It also explains the 402 challenge behavior when payment is omitted, which is important operational context.

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 description is 4 sentences, starts with the cost, and packs purpose, features, execution model, and payment flow efficiently. Each sentence adds information without redundancy, though the payment behavior is repeated from the schema.

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?

Given no output schema, the description adequately conveys what the tool returns: revoke calldata or a 402 challenge. It covers the payment requirement, security model, and free alternative, making it sufficient for a user to invoke the tool correctly. Some output structure details are missing but not critical.

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 input schema already provides complete descriptions for all three parameters (100% coverage). The description primarily reinforces the payment parameter by mentioning x_payment and USDC on Base, but does not add significant new meaning beyond the schema's existing details.

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 clearly states the tool scans wallet ERC-20/721 approvals, ranks exposure, flags risky spenders, and returns revoke calldata. It distinguishes itself from the free sibling `approvals_free` and other tools like `simulate` and `token_safety` by its specific focus on approvals and payment model.

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?

The description tells users this is the paid version, noting payment is $0.01 and that without payment it returns a challenge, while `approvals_free` is the free teaser. It also clarifies that users execute the calldata themselves, which sets expectations. However, it does not explicitly contrast with other scan tools like `simulate` or `token_safety` beyond the tool name.

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