cancel_job

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Discloses that the partial result is discarded and not recoverable, that pending jobs are unaffected, and the need for a reachable ComfyUI server. No annotations are provided, so description carries the full burden and succeeds.

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?

Three sentences with no waste; front-loaded with the core action and key constraints. Every sentence earns its place.

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 tool with one optional parameter and no output schema, the description covers purpose, behavior, return value, and prerequisites completely.

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% for the single parameter, but the description adds value by explaining the prompt_id's optional behavior: 'only interrupts the running job when its prompt_id matches; omit to interrupt whatever is currently running.'

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 tool interrupts the currently running ComfyUI job, and distinguishes it from siblings like cancel_queued_job and clear_queue, providing specific verb and resource.

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?

Explicitly says when to use this tool (for the actively executing job) and when to use alternatives (cancel_queued_job for a specific pending job, clear_queue for all pending).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.