cancel_scheduled_email

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states a key side effect: 'The draft stays in the Drafts folder, so the content is not lost.' This meaningfully clarifies what the cancellation does and does not do. It could further mention errors for invalid scheduleId or whether cancellation is reversible, but for a single-parameter operation this is reasonably transparent.

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 sentences, no filler. The action and parameter source are front-loaded, and the draft-preservation note is a valuable addition without bloat.

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 tool with one required parameter and no output schema, the description is complete. It states the operation, identifies the parameter's source, and clarifies the side effect. An agent has enough information to call the tool correctly.

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 only defines scheduleId as a minLength-1 string with no description, so coverage is 0%. The description compensates by explaining that scheduleId identifies a pending scheduled send and comes from send_email with sendAt or list_scheduled_emails. This gives the agent practical knowledge for populating the parameter, though it does not specify format beyond the source.

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 uses a specific verb and resource combination: 'Cancel a pending scheduled send by scheduleId.' It clearly identifies the operation as distinct from siblings like delete_draft or send_email, and it names the source of the scheduleId, eliminating ambiguity about what the tool acts on.

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 implicitly tells the agent when to use this tool: when a scheduled email exists and needs to be canceled. It explains where to obtain scheduleId (from send_email with sendAt or list_scheduled_emails), which is a clear usage prerequisite. It does not explicitly contrast with alternatives like delete_draft, but the mention that the draft remains makes the distinction reasonably clear.

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