Stop an active agent task immediately using its unique task ID. Prevents unwanted or stuck processes from continuing to run.
Cancel a currently running agent task.
| Name | Required | Description | Default |
|---|---|---|---|
| taskId | Yes | Task ID to cancel |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavioral traits. It doesn't explain whether cancellation is immediate or graceful, if it can be undone, what happens to results, or any side effects. This is a significant gap for a cancellation operation.
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, clear sentence that directly states the action. It is appropriately sized but could be slightly more informative without being verbose.
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 destructive nature, lack of annotations, and no output schema, the description should provide more detail on what happens after cancellation (e.g., state changes, resource cleanup, return codes). It is incomplete for a safe agent decision.
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% and the schema already describes taskId as 'Task ID to cancel'. The description adds no extra meaning beyond this, so a baseline score of 3 is 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?
The description clearly states the verb 'Cancel' and the resource 'currently running agent task', which differentiates it from siblings like agent_send or agent_status. However, it doesn't explicitly mention that the task must be running versus already completed, which is a minor gap.
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?
No guidance is provided on when to cancel a task vs. waiting for completion, or when alternatives like agent_review_loop might be more appropriate. The description gives no context on prerequisites or consequences.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.