job_cancel

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does disclose a meaningful side effect—terminating the job's child process group—which goes beyond the tool name. But it does not mention irreversibility, idempotency, or whether job output remains accessible after cancellation.

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 focused sentence with no filler. The core action and the key side effect are front-loaded, making it easy to parse quickly.

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?

The tool is simple, has one parameter, and an output schema exists, so return-value documentation is not necessary. Still, the description omits practical context like where to find job_id (e.g., from job_status) and what state the job enters after cancellation. It is minimally adequate but leaves 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 coverage is 0% and job_id has no description beyond its name and type. The tool description does not explain how to obtain a valid job_id or what format it expects, leaving the only parameter under-specified. The parameter name provides minimal semantic value on its own.

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 uses a specific verb ('Cancel') with a clear resource ('running background job') and adds 'its child process group', which distinguishes it from job_status, job_output, and other non-cancel tools. An agent can tell this is the cancellation operation without opening the schema.

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 background job' gives clear context: this tool applies to active background jobs, not completed ones. However, it does not explicitly name alternatives or say when not to use it, though no direct cancel-sibling exists among the listed tools.

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