a2a_cancel_task

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the cancel action and the non-terminal constraint, but does not describe side effects (e.g., state transition), error behavior for terminal tasks, idempotency, or permissions. This is a significant gap for a mutation tool.

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 two concise sentences. The first sentence states the core purpose, and the second adds a critical constraint. Every word earns its place, with no filler or redundancy.

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 tool's simplicity (one parameter, no output schema, no annotations), the description covers the basic purpose and a key constraint. However, it lacks behavioral completeness: it does not explain what happens after cancellation (e.g., final status), how errors are reported, or whether there are any side effects. It is minimally viable but not rich.

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?

The input schema has 100% coverage for the single parameter task_id, with a description 'Task ID to cancel'. The tool description does not add any further parameter-level detail, so the baseline of 3 applies since the schema already documents the parameter adequately.

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 action ('Cancel') and the resource ('an A2A task'), which distinguishes it from sibling tools like a2a_submit_task, a2a_get_task, a2a_list_tasks, and a2a_respond_task. The verb+resource combination is specific and unambiguous.

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 a clear usage condition: 'Only non-terminal tasks can be canceled.' This implies the tool should not be used on terminal tasks, which is a when-not guideline. However, it does not explicitly name alternative tools or explain contexts where cancellation might be inappropriate beyond the terminal status.

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