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

With no annotations, the description carries full burden. It does disclose the key behavioral trait — this is a side-effect-free builder that neither executes nor moves payment — but says nothing about whether credentials/signing are required, whether the request is one-shot, or what the returned request contains.

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 sentences, front-loaded with the core action and followed by the crucial non-execution caveat. The long dash-delimited list of covered items is slightly dense but every element is informative, with 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?

For a request-builder with no output schema, the agent still needs to know the shape of the returned request (URL, method, headers, body) and how to use it. The description covers the conceptual purpose but leaves the return contract and execution hand-off unspecified.

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% and the single parameter 'did' is undocumented in both schema and description. The description mentions an 'owner key' but never connects it to the 'did' input or explains its format (e.g., did:key vs a plain key), so it fails to compensate for the coverage gap.

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 artifact ('Returns the exact HTTP request') plus the resource and purpose (checking a Close Call owner key via x402). It clearly frames itself as a request-builder rather than an executor, though it doesn't explicitly contrast itself with the other *_request siblings.

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 'does NOT run it or move any payment itself' clause implies the agent must hand the returned request to something else, which is useful implied guidance. However, there is no explicit when-to-use condition, no named alternative for actually executing the request, and no prerequisite information.

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