job_cancel
Terminates a running job and its entire process tree to stop execution.
Instructions
Cancel a running job (kills its process tree).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes |
Terminates a running job and its entire process tree to stop execution.
Cancel a running job (kills its process tree).
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true. The description adds useful behavioral context by specifying that cancellation kills the process tree. It does not cover authorization needs, return format, or whether the operation waits for termination.
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, front-loaded sentence with no wasted words. The key action and its destructive effect are communicated immediately.
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 simple destructive tool with rich annotations and no output schema, the description states the effect but leaves the required 'id' parameter unexplained and gives no usage guidance versus alternatives. It is minimally adequate but has clear gaps.
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 single required parameter 'id' is undocumented in both schema and description. The description does not explain the format, source, or meaning of the job identifier beyond the obvious implication from 'job'.
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 and resource: 'Cancel a running job'. The parenthetical clarifies the scope by noting it kills the process tree. It is clear but does not explicitly differentiate from sibling tools like kill_process or process_stop, which could cause confusion for an agent.
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 explicit guidance on when to use job_cancel versus alternatives such as kill_process, process_stop, or job_status. Usage is only implied by the tool name and the phrase 'running job'. No exclusions or prerequisites are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.