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

Annotations already mark destructiveHint=true, but the description adds specific behavioral details: the need for user confirmation and the non-refundable credit policy. This goes beyond the annotation and helps the agent understand consequences.

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, efficient sentence that conveys the core action and critical caveats. No wasted words; the warning is front-loaded and impactful.

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 simple cancellation tool with one parameter and no output schema, the description covers the action, side effects, and user confirmation. It lacks details on return values, but that's acceptable given the simplicity and the annotations.

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 single parameter task_id is self-explanatory, but the description does not explicitly explain its meaning or format. With 0% schema coverage, the description could have added a line like 'task_id is the ID of the running task to cancel,' but the name is clear enough.

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 a running task, with a specific verb and resource. It distinguishes from siblings like retry_task or get_task by specifying 'running task', implying it only applies to tasks in progress.

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?

It provides usage context: confirm with the user first and warns about non-refundable credits. It doesn't explicitly state when not to use it or mention alternatives, but the guidance is actionable for the agent.

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