Find paid x402 services the agent can call

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

Annotations already provide readOnlyHint=true and openWorldHint=true, covering safety and dynamic results. The description reinforces read-only behavior and adds context about the live network search, but doesn't disclose additional behavioral traits beyond what annotations offer.

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 three sentences with no wasted words. The first sentence immediately states the core action, and subsequent sentences add essential context on workflow and safety.

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 5 parameters, 1 required, and no output schema, the description provides a high-level overview of returns but lacks detail on result structure (e.g., field names, array format). It's adequate but not fully complete for invoking the tool correctly.

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 coverage is 100%, so the baseline is 3. The description doesn't add new semantic details about parameters beyond what the schema provides. It mentions output fields but not parameter specifics, so it barely meets the baseline.

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 it searches a live network for paid services (HTTP APIs and MCP tools). It specifies the return fields (price, networks, resource URL) and distinguishes from siblings like pay_and_call (for using services) and inspect_endpoint (likely for inspection).

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 explicitly tells agents to pass a resource into pay_and_call to use it, providing clear context on when to use this tool versus its sibling. It also marks the tool as read-only, though it doesn't explicitly exclude alternative scenarios.

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