Cancel a non-terminal task with a retry-safe idempotency key to avoid duplicate cancellations. Use it when a task is still active and needs safe, repeatable status updates.
Cancel a non-terminal task using a retry-safe idempotency key.
| Name | Required | Description | Default |
|---|---|---|---|
| task_id | Yes | ||
| idempotency_key | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It does disclose two useful traits—that the operation is retry-safe via an idempotency key, and that only non-terminal tasks are eligible—but is silent on permissions, what terminal state the task lands in, and side effects on in-flight work.
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?
A single front-loaded sentence with zero filler; the critical qualifier and the idempotency mechanism are both delivered in one pass.
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?
An output schema exists, so return values need not be explained, and the safety story is partly covered by the idempotency note. However, for a mutation tool with no annotations the description leaves key operational context—permissions and cancellation side effects—unstated.
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 0% for two parameters. The description compensates for idempotency_key by explaining its retry-safe purpose, and task_id is self-evident from the name, but no format, uniqueness scope, or reuse semantics are given for the key.
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 states a specific verb (Cancel) and resource (task) and adds the qualifier 'non-terminal', which tells an agent this only applies to active/pending work. It implicitly distinguishes itself from siblings like list_tasks and get_task, though it does not explicitly name the closest alternative (update_task_status).
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?
There is no guidance on when to cancel versus transitioning a task via update_task_status, nor any stated prerequisites or error conditions beyond the 'non-terminal' hint. The agent must infer the routing decision entirely on its own.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.