Cancel a scheduled email

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, so the description does not need to restate that. However, it adds valuable context beyond annotations by specifying the cancellation is 'locally and, when needed, in Exchange', disclosing the conditional scope of the operation. This is additional behavioral information not captured in the schema or annotations.

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 a single, front-loaded sentence with no filler. Every word adds value, specifying the action, the target, and the conditional scope. It is concise yet complete.

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 the tool's low complexity (one parameter, one action), the presence of an output schema, and annotations covering safety (destructive, idempotent), the description is complete enough for an agent to invoke it correctly. It clearly states what will happen and the scope, with no missing critical information.

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?

The schema covers the single parameter 'id' fully (100% description coverage), so the description does not need to add parameter details. It doesn't, and the baseline is 3 given high schema coverage. No additional meaning is provided beyond the schema, but none is required here.

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?

Description states a specific verb ('Revoke'), a specific resource ('pending scheduled email'), and a scope ('locally and, when needed, in Exchange'). This clearly distinguishes it from sibling tools like schedule_email (creating) and list_scheduled (listing). An agent can immediately tell what this tool does without consulting other definitions.

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 description implies usage (cancel scheduled emails) but provides no explicit guidance on when to use it versus alternatives, nor any exclusions or prerequisites. It does not mention, for example, that it should not be used for already-sent emails. Only implied usage is present, no explicit routing.

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