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

With annotations only covering readOnlyHint=false and openWorldHint=true, the description adds genuine behavioral context: the bearer-token auth requirement, the return payload ('the code and plain instructions'), and a conditional availability gate. The gate is vague ('that check is off'), leaving an agent unsure what configuration toggles it.

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?

Four short sentences with zero filler, front-loading the core action before auth, return, and availability details. Every sentence carries information an agent would otherwise have to discover empirically.

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 single-param, single-purpose tool with no output schema, the description covers action, auth, return content, and an availability constraint. It would be complete if it hinted at the follow-up step (verifying the returned code) or clarified the ambiguous 'check' gate.

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% and the single domain parameter is fully documented, so the schema already carries this load. The description reinforces the one-domain constraint ('one domain') but adds no format or validation detail beyond the schema 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 uses a specific verb ('Ask for') and resource ('a one-time code for one domain') and anchors it to a known operation ('Same as POST /api/proofs'). It is unambiguous what the tool does, though it never names the sibling it differs from (e.g. verify_certification), so differentiation relies on inference.

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 states a prerequisite ('Requires a bearer token') and an explicit exclusion ('Not available when that check is off'), which gives an agent real context for when the call will work. It does not name alternatives such as verify_certification to complete the request/verify flow, so routing guidance is incomplete.

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