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

The destructiveHint annotation already flags the mutation, but the description adds genuine value by spelling out the concrete consequence: signers can no longer sign. It stops short of covering idempotency, auth requirements, or reversibility, so it is strong but not exhaustive.

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 terse sentences: purpose first, destructive consequence second, endpoint third. Nothing is wasted and the most decision-relevant information is front-loaded.

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-parameter destructive tool with no output schema and full annotation coverage of destructiveness, the description supplies everything needed: what it does, the condition under which it applies, and the consequence. Return values are unnecessary here.

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?

There is only one parameter and schema description coverage is 100%, with the schema itself stating it is 'the id of the incomplete signature request to cancel.' The description adds no format, source, or id-syntax detail beyond the schema, so the baseline of 3 applies.

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?

States a specific verb (cancels) and resource (signature request) and narrows the scope to 'incomplete' requests, which no sibling tool touches. An agent can immediately tell this is the terminal/cancel action versus get/list/remind/send siblings.

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?

The precondition 'incomplete signature request' acts as clear usage context, and 'Destructive — signers can no longer sign' warns the agent about consequences. It does not, however, name alternatives (e.g., remind_signature_request for nudging instead of canceling) or state what happens if the request is already complete.

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