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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context beyond the annotations: a rate limit and the side effect that the user separately receives an email with the signed PDF, which prevents an agent from treating this call as the delivery mechanism.

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?

Three short sentences, front-loaded with the action and the return states, with the rate limit and side-effect note trailing. The status enumeration is long but earns its place by substituting for a missing output schema; nothing is padded.

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?

With no output schema, the description usefully enumerates the return statuses and covers the polling limit and the email side effect. The remaining gap is authentication context for request_id/request_token, which is only half-covered by the schema, but for a simple read-only status check this is close to complete.

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 only 50%: request_token is documented in the schema, but request_id has no description anywhere. The prose mentions no parameters at all, so it does not compensate for the undocumented half — the agent gets no help on what request_id should be or why both are listed with zero required fields.

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 names a specific verb and resource ('Check whether the signer has signed') and enumerates the possible outcome states, which sharply distinguishes it from siblings like find_signature_requests (listing) and send_for_signature (mutation). An agent can identify the tool's role without opening the schema.

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 a polling constraint ('Do not check more than once a minute'), which is real usage guidance, but never states when to prefer this over find_signature_requests or cancel_signature_request, nor any prerequisite for calling it. Usage is implied (poll a single request) rather than contrasted with alternatives.

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