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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the tool does not execute the check or move payment itself, and it mentions x402 payment context and raw signal return. It does not cover auth needs, rate limits, or whether calling this tool has its own side effects.

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 front-loaded sentence that immediately states what is returned. The parenthetical detail is dense but relevant, and the caveat about not executing or moving payment is placed at the end. It is efficient, though the phrasing is slightly convoluted.

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 one-parameter request-builder tool with no output schema and no annotations, the description covers the core purpose and non-execution behavior. However, it leaves the did parameter semantics and the exact shape of the returned HTTP request unclear, which are important for correct invocation.

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?

The schema has one required parameter, did, with 0% description coverage. The description implies the DID is the subject being checked, but it gives no format, signing requirements, or validation details for the parameter, so it only minimally compensates for the schema 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?

The description states a specific verb (Returns) and resource (the exact HTTP request needed to check whether a signed DID posts templated filler), and it clearly separates itself from an executor by saying it does NOT run the request or move payment. It does not name sibling tools, but the purpose is otherwise unambiguous.

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 context for when this tool is appropriate: when the caller needs the HTTP request rather than execution. It also states a key exclusion: the tool does not run the request or move payment. No alternative sibling is named for actually executing the request, so it falls short of a 5.

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