Submit a wallet-generated x402 PAYMENT-SIGNATURE for a previously quoted product. Use exactly the same arguments. Never provide a private key or seed phrase. request_id enables safe result replay.
| Name | Required | Description | Default |
|---|---|---|---|
| product | Yes | ||
| arguments | Yes | ||
| request_id | No | ||
| payment_signature | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden and adds safety guidance (never provide private key or seed phrase) and idempotency semantics (request_id enables safe replay). It stops short of explicitly stating that submitting a signed payment may execute an irreversible financial transaction, but 'PAYMENT-SIGNATURE' and 'Submit' convey the core behavior.
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?
Three short sentences, each earning its place: purpose, argument-matching rule, safety warning, and replay semantics are all front-loaded. No filler.
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?
The description covers the required flow (prior quote, same arguments, wallet-generated signature, optional request_id), and the output schema removes the need to document return values. The only material gap is an explicit warning that this action can finalize a real payment.
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 0%, so the description must compensate. It does: product and arguments map to the previous quote, payment_signature must be wallet-generated rather than credentials, and request_id controls replay. It doesn't enumerate argument shapes, but 'use exactly the same arguments' is a strong semantic guide.
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 states a specific operation (submit) and resource (wallet-generated x402 payment signature), tied to a prior quote. This clearly separates it from the sibling get_* tools, which are retrieval actions.
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?
It gives clear when-to-use context: only for a previously quoted product, with arguments identical to that quote. It does not explicitly name alternatives or exclusions, but the sibling set is retrieval-oriented and the 'previously quoted' condition is a sufficient routing signal.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The four get_*_ayment tools all create live x402 challenges and differ only by product, while get_quote and get_example_payment both provide example input data — creating real selection ambiguity. Descriptions do clarify the product and side-effect differences, but an agent must read carefully to avoid picking the wrong one.
All tools use lowercase snake_case with a verb prefix, and the get_X_payment pattern for challenge creation is consistent. However, 'get' is overloaded to cover both free reads that create no side effects and challenge creation calls, and get_payment_preflight_payment has a redundant 'ayment' that muddies the naming pattern.
Eight tools map cleanly to the paid-evidence workflow: status check, quote, four product-specific challenge creators, payment submission, and a capability-request escape hatch. Each tool earns its place, and the count is well-scoped for a niche paid API.
The core quote→challenge→submit→result flow is covered, and request_capability is a good gap-filler for missing products. Minor gaps remain: there is no explicit result-retrieval tool beyond request_id replay, and product discovery is implicit through get_quote and get_service_status rather than a dedicated list endpoint.
