pay

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

With no annotations provided, the description carries the full burden. It does disclose the core behavior—calling an endpoint and conditionally paying USDG—and mentions budget caps. However, it omits important behavioral context such as irreversibility, authentication requirements, failure handling, rate limits, or what happens if the endpoint returns a non-402 response.

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 a single dense, front-loaded sentence with no wasted words. It communicates the main action and constraint efficiently. However, it is terse enough that some operational clarity is sacrificed.

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 no annotations and no output schema, the description is incomplete. It lacks return value information, failure modes, budget cap details, authentication requirements, and any indication of what response the caller should expect. An agent would be uncertain about the full consequences of invoking this tool.

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 only 33% (body is described in the schema), and the description adds no parameter-level meaning. The required 'url' parameter is not explained beyond being an endpoint, and 'method' has no semantic guidance. Since coverage is low, the description needed to compensate but did not.

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 action—'Call a machine-payable (x402) endpoint'—and the exact condition for payment: 'pay in USDG if it answers 402.' This clearly distinguishes it from sibling tools like get_balance, history, and create_session, which serve different purposes.

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?

No guidance is given on when to use this tool versus alternatives, when not to use it, or what prerequisites exist (e.g., sufficient balance, valid session). The only hint is 'Budget caps apply,' which is a constraint rather than usage guidance.

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