Cancel Session Job

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

The description adds behavioral context beyond annotations: it notes that cancellation is a request (not immediate), requires specific tokens, and mentions AbortSignal support. Annotations already indicate idempotentHint=true and destructiveHint=false; the description does not contradict them.

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 concise (4 sentences) and front-loads the purpose. It is not verbose, but the lack of parameter descriptions reduces structural clarity.

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?

With 5 parameters, no output schema, and 0% schema coverage, the description is incomplete. It explains purpose and some constraints but omits parameter details, return values, and error handling, leaving agents underinformed.

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%, so the description must compensate. It only mentions reason's maxLength (300 chars). It does not explain session_id, job_id, caller, or response_format, leaving agents without crucial parameter semantics.

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 cancels running background jobs in a durable session. It uses a specific verb-resource pair ('request cancellation' + 'background jobs in a durable session'). It distinguishes from siblings because many session_ tools exist, but only this one targets cancellation.

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 description specifies token requirements and restrictions (another peer cannot cancel), providing some usage context. However, it does not explicitly state when to use this tool versus alternatives like session_doctor or session_events, nor does it mention when not to use it.

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