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

With no annotations provided, the description carries the full burden of disclosing behavior. It adds one useful trait—'the proof is the record; no signature needed'—suggesting this is a lookup-style verification rather than a cryptographic signature check. However, it does not disclose side effects, return values, failure behavior, or whether this operation is read-only.

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 short and front-loaded, with no wasted words. Both sentences contribute meaning, but the second sentence is cryptic and could be clearer. It is concise, though somewhat under-specified for the tool's needs.

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 no output schema, no annotations, and 0% schema description coverage, the description is far from complete. An agent cannot tell what the result of verification looks like, what keyId means, what values origin accepts, or what failure conditions exist. The description leaves too much unspecified for reliable tool 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?

Schema description coverage is 0%, so the description must compensate for the undocumented parameters. It vaguely implies that 'origin' relates to a domain, but it gives no explanation of 'keyId', no format expectations, and no relationship between the two parameters. This is insufficient parameter guidance.

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 ('Check') and a specific resource ('a domain's ownership proof'), so an agent can understand the core action. It does not mention how this differs from any sibling tool, but no obvious sibling performs the same function, so it remains clear.

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?

There is no guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions. The phrase 'no signature needed' hints at a condition, but it does not explain when verification is required or how it relates to other domain-related tools.

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