task.cancel

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

Beyond the destructiveHint annotation, the description adds meaningful behavioral detail: the operation is 'best-effort', it stops running processes, and it preserves the worktree. This tells the agent exactly what will be affected and what will not, which is directly useful for risk assessment.

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?

One sentence with the action front-loaded and zero filler. Every clause contributes operational information: active scope, best-effort behavior, process stopping, and worktree preservation.

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 one-parameter tool with no nested objects and no output schema, the description plus schema is sufficient to invoke it correctly. It covers the key decision factor (active task) and the observable effect, so nothing essential is missing.

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 schema only documents task_id as a non-empty string, so the description's 'ACTIVE Task' qualifier adds useful selection semantics: the provided id must reference an active task. It does not explain how to obtain the id or what happens with an invalid/inactive one, but for a single obvious parameter this is a reasonable contribution.

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 uses a specific verb ('Cancel') with a specific resource ('Task') and a scope qualifier ('ACTIVE'), making the tool's purpose unmistakable. 'ACTIVE' also distinguishes it from finishing or cleaning up a completed/abandoned task, and the action word separates it from process.cancel.

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 clearly states the precondition ('ACTIVE Task') and the expected effect ('stopping its running processes while preserving the worktree'), so an agent knows when cancellation is appropriate. It does not explicitly mention alternatives like process.cancel, task.finish, or task.cleanup, so it stops short of a full when/when-not comparison.

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