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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the destructive nature is covered. The description adds 'This cannot be undone' which reinforces irreversibility but is somewhat redundant with destructiveHint. It also notes 'pending' scope, which is useful. Given the annotations cover the main behavioral profile, the description provides marginal extra context.

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 short sentences, front-loaded with the action and resource. No filler or redundancy; every word contributes.

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?

The tool is simple with a single parameter and an output schema. The description covers the essential purpose and the irreversible nature. It could mention what happens after cancellation or that only pending requests are eligible, but these are implied. Given the simplicity, it is sufficiently 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 coverage is 100%, so the parameter 'request_id' is fully described in the schema as 'The ULID of the signing request to cancel.' The description adds no additional parameter information, which is acceptable given high schema coverage.

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 action (cancel) on a specific resource (pending document signing request). It clearly distinguishes from siblings like send-signing-request-tool and list-signing-requests-tool. The verb and object are 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 implies when to use: for cancelling a pending request. It doesn't explicitly state when not to use or name alternatives, but the sibling set makes the context clear. Could be improved by noting it only applies to pending requests, though that is already mentioned.

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