Interrupt a subagent

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

With no annotations provided, the description carries the full burden. It transparently discloses that it cancels the in-flight turn, drops queued messages, and preserves session resumability. This goes beyond a simple action and gives clear behavioral context, though it omits potential side effects like partial results or error conditions.

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 sentence that front-loads the core action and then adds the key behavioral nuance about session persistence. Every word contributes value, and it is appropriately sized for a one-parameter tool.

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 tool with one parameter and no output schema or annotations, the description covers the essential behavior: what it cancels, what it drops, and the post-condition of resumability. It is sufficient for an agent to use correctly, though it could mention edge cases like interrupting an idle subagent.

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 already documents the parameter fully (subagent handle returned by spawn) with 100% coverage. The description adds no additional semantic information about the parameter, so the baseline score of 3 applies.

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 an in-flight turn and drops queued messages, with the session remaining alive and resumable. It is specific about the action and resource, though it does not explicitly name sibling alternatives, it implies a distinction from stop (which likely terminates).

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 when to use this tool by noting the session stays alive and resumable, suggesting it is for temporary pauses. However, it does not explicitly compare with siblings like stop or resume, nor state when not to use it. Guidance is implied rather than explicit.

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