cancel_run

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

Annotations already declare destructiveHint=true and idempotentHint=true. The description's note about 'stable results on repeated cancellation' merely restates the idempotency hint without adding new behavioral context, such as what happens to the run, side effects, or permissions required. It adds no value beyond annotations.

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, concise sentence with no fluff. It states the core action and the idempotency property efficiently. The structure is front-loaded with the primary purpose.

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?

Given the low complexity (one parameter, no output schema), the description is minimal. It omits key contextual details like the effect on the run lifecycle (e.g., will it stop emitting events?), whether cancellation is reversible, or any return value. An agent would have to infer behavior from the annotations alone, making the description insufficient for full understanding.

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 parameter 'relayRunId' is not documented in the schema, and the description does not explain it. Although the name is somewhat self-explanatory, the description fails to compensate for the lack of schema documentation, providing no clarification on its format, purpose, or expected values.

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 'cancel a still-running Cursor SDK run', specifying the verb (cancel) and resource (run). It is distinct from sibling tools like start_run, get_run, etc., though it does not explicitly name alternatives. The purpose is unambiguous and sufficiently specific.

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 implies the tool is for runs that are still executing ('仍在执行'), but it provides no explicit guidance on when to use it versus alternatives like wait_run or how it relates to other lifecycle operations. No exclusions or conditions are given beyond the implicit 'still running' state.

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