q402_request_pay

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

With no annotations, the description carries the full burden and excels. It clearly warns 'MOVES FUNDS' and details exact prerequisites: 'requires confirm:true, a live API key, and Q402_ENABLE_REAL_PAYMENTS=1'. It also explains the two-phase consent flow ('Omit on the FIRST call... re-call with the SAME requestId plus this token to execute') and the non-redirectable nature of the payment.

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 dense but every sentence earns its place: purpose, usage, safety warning, prerequisite, precursor step, and differentiation from siblings. It is front-loaded with the core action and remains readable despite its length.

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?

This is a fund-moving, two-phase consent tool with no output schema, and the description covers all necessary context: exact usage flow, prerequisites (confirm, API key, env var), safety constraints (non-redirectable), and the billing-workflow position. It is as complete as one could expect for a tool of this 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?

Although schema coverage is 100%, the description adds critical semantic context beyond the schema. It explains that requestId determines 'the exact amount + token + recipient the request specifies - you cannot redirect or change them,' and clarifies the consentToken's re-derivation from request terms, which is not in the schema. This meaningfully enhances parameter understanding.

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 opens with a specific verb+resource: 'Pay a Q402 payment request from your own Agent Wallet, gaslessly.' It clearly distinguishes this from q402_pay by framing it as the agent-to-agent billing path: 'agent A bills with q402_request_create, agent B settles here.' This is a clear, unambiguous purpose.

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?

Provides explicit when-to-use guidance: 'Give it a req_ id (from a /pay link, a 402 Payment Required response, or whoever billed you)' and advises 'Call q402_request_status first to show the user what they're paying.' It also contrasts with q402_pay and q402_request_create, making the appropriate context salient.

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