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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is partly covered. However, the description adds nothing beyond restating the title: it does not say whether cancellation is reversible, whether progress is lost, or what happens if the job has already finished.

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 front-loaded sentence with zero filler. Efficient, though arguably too terse for the information gaps it leaves.

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 tool with annotations covering the safety flags and no output schema, the description is minimally viable. It still leaves open where jobId comes from and what the failure modes are, so an agent has some inference to do.

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% for the single parameter jobId, so the description must compensate and does not — jobId is never mentioned, nor is its format or how to obtain it (e.g. from list_jobs or get_job_status). The name is only marginally self-explanatory.

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?

States a specific verb (cancel) and resource (background job) with clear scope. It stands apart from destructive siblings like delete_block, but gives no differentiation from the closely related get_job_status and list_jobs.

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?

'Running' implies the job must currently be active, but there is no explicit when-to-use, no prerequisites, and no mention of how it relates to list_jobs or get_job_status, which are the natural companions for obtaining a jobId.

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