cancel_scheduledCancel a scheduled email and remove it from the queue, deleting the associated draft so it is not sent.
Cancel a scheduled email. Removes it from the queue and deletes the associated draft.
| Name | Required | Description | Default |
|---|---|---|---|
| schedule_id | Yes | Schedule ID to cancel |
Changes observed during successful MCP inspections.
v0.6.0Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v0.2.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is covered. The description adds a genuine side-effect disclosure beyond annotations: the scheduled item is removed from the queue and the associated draft is deleted, which is non-obvious and important. It stops short of stating reversibility or failure modes.
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 immediately followed by the destructive side effect. No filler or redundancy.
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 one-parameter destructive mutation with full annotation coverage and no output schema, the description supplies what matters most: the queue removal and draft deletion. It could be complete with a note on whether cancellation is permanent or error behavior, but the essentials are present.
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 description coverage is 100% for the single schedule_id parameter, so the schema already documents it fully. The description adds no format, source, or constraint detail beyond the schema, making the baseline 3 appropriate.
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 ('Cancel') and resource ('scheduled email'), clearly distinguishing it from siblings like delete_email and list_scheduled. It does not explicitly name an alternative sibling by name, but the action is 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?
The description gives no when-to-use context, prerequisites, or named alternatives. Usage is only implied by the tool name ('scheduled'), with no guidance on how it differs from delete_email or when a scheduled item cannot be cancelled.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.