cancel_email

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

No annotations are provided, so the description must carry full burden. It discloses mutation (cancel) and precondition (unsent), but omits what happens if the email is already sent, whether cancellation is reversible, authentication requirements, or error handling.

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 concise sentence with no fluff. It is appropriately front-loaded and easy to parse, though it could be slightly more structured (e.g., separate condition).

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 low complexity (1 required param, no output schema, no nested objects), the description is minimally adequate. However, it lacks details on error scenarios, idempotency, and success feedback, which would improve completeness.

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%: the only parameter 'id' has a clear description 'The scheduled email's ID.' The tool description does not add beyond this, meeting the baseline for 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 'Cancel a scheduled email that has not been sent yet' clearly specifies the action (cancel), resource (scheduled email), and condition (not sent). It distinguishes from sibling tools like send_email, get_email, and list_domains.

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 for cancelling unscheduled emails but provides no explicit guidance on when to use versus alternatives, nor any prerequisites or conditions. The precondition 'has not been sent yet' is stated but not elaborated.

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