Cancel a running job by job ID while preserving any finished outputs, so you can stop active work without losing completed results.
Cancel a running job; finished outputs are kept.
| Name | Required | Description | Default |
|---|---|---|---|
| job_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false and destructiveHint=false, and the description explains why cancellation is not fully destructive: 'finished outputs are kept.' That is genuine added context. However, it is silent on what happens to in-progress work, whether cancelling an already-finished job errors (annotations say idempotentHint=false), and whether cancellation is immediate.
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 tight sentence with the core action front-loaded and the state-retention caveat attached. No filler.
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, annotation-covered tool with no output schema, the definition is minimally sufficient: it says what is cancelled and what survives. It leaves gaps an agent would care about, specifically where to get a valid job_id and how errors/duplicate cancels behave.
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%, and the description never mentions job_id at all. The single parameter is self-named and required, so an agent can infer it, but the description adds no format, source, or validity information to compensate for the empty schema.
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?
'Cancel a running job' gives a specific verb+resource that is clearly distinct from siblings like job_status and start_batch. The added clause about outputs surviving makes the intent sharper, though it does not name sibling tools or contrast itself with them.
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 phrase 'running job' implies the precondition that the job must be in flight, and the verb implies when to use it. But there is no explicit when-not guidance (e.g., finished/failed jobs), no mention of alternatives such as letting the job complete, and no pointers for obtaining a job_id.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.