Pay x402 Resource

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

With no annotations provided, the description carries the full behavioral burden and does disclose meaningful traits: the submission goes through the Veil relay without a WalletChan popup and requires explicit user approval with confirm=true. Gaps remain around irreversibility of the payment and authentication/keypair requirements, but the relay-path and approval disclosures are genuinely useful 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?

Two tightly written sentences with no padding, front-loading the core action ('Pay a Veil-supported x402 ... resource') before the approval requirement. Efficient and well-ordered, though the second sentence is dense enough that it could be slightly clearer.

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 payment tool with 8 parameters, no annotations, and no output schema, the definition covers purpose and the approval/relay behavior but omits failure handling, what a successful payment returns, and the authentication context. Adequate but with clear gaps relative to the tool's complexity.

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 high (88%), so the schema already documents url, body, method, headers, confirm, maxPayment, forceFresh, and payerIndex. The description only restates that maxPayment and confirm are required, adding no new semantic detail such as payment format or forceFresh/payerIndex behavior, so the baseline 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?

States a specific verb and resource: paying a Veil-supported x402 v2 exact Base USDC resource from private Veil USDC, which is far more precise than a generic 'pay' statement. However, it does not name or contrast against relevant siblings such as veil_x402_quote or agent_x402_pay, so differentiation relies on the reader already knowing the ecosystem.

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 gives an implied condition of use ('requires ... confirm=true after explicit user approval') and a rationale (no WalletChan popup), which is useful context. But it never states when to prefer this over veil_x402_quote or agent_x402_pay, nor any when-not guidance, so usage is only inferable.

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