Cancel a Harness run

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

Annotations already indicate destructiveHint=true, readOnlyHint=false, and idempotentHint=true. The description adds the subtle behavioral trait that this is a 'request' for cancellation rather than an immediate cancel, but it does not explain what happens to the run, whether cancellation is reversible, or any downstream effects.

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 filler or repetition. It is front-loaded and easy to parse, though it is arguably too brief to carry the behavioral and usage context needed for a destructive operation.

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 destructive mutation tool with no output schema and no usage guidance, the description is underspecified. It omits cancellation semantics, prerequisites, effects on the run, and any indication of what the agent should expect after invoking it.

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%, and the description adds no meaning about runId or idempotencyKey. The schema itself defines formats and constraints, but the description does not explain the purpose of either parameter, when idempotencyKey should be used, or how runId relates to a cancellation flow.

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 states a clear action ('Request cancellation') and a clear resource ('a Harness run'), which matches the title and tool name. It is distinguishable from siblings like 'start_run' and 'steer_run', though it does not explicitly differentiate itself from them.

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 provides no when-to-use or when-not-to-use guidance and does not mention alternatives. An agent is not told when cancellation is appropriate, what conditions are required (e.g., run must be active), or how this differs from related operations.

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