stop_subagent

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

The description clarifies the two modes of operation (interrupt vs. kill-window), which adds context beyond the destructiveHint annotation. However, it does not disclose potential side effects such as cleanup of child processes or consequences of killing the tmux window. The annotation already flags destructiveness, so the description offers modest additional value.

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, front-loaded with the action verb and resource, and contains no redundant or extraneous words. It is an exemplar of concise and efficient communication.

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, the comprehensive schema, and the destructiveHint annotation, the description covers the essential purpose and safety profile. Because an output schema exists, return values are not required. A brief note about handle formats or typical use cases might add slight value, but overall it is sufficiently complete.

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 fully documents both parameters (handle and kill_window) with descriptions and a default value, covering 100% of the parameter semantics. The description adds no additional meaning beyond the schema, so the baseline of 3 is appropriate.

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 the specific verb 'Interrupt or kill' and clearly identifies the resource 'a running subagent'. This unambiguously distinguishes it from sibling tools like launch_subagent, check_subagent, and list_subagents. The purpose is immediately understandable.

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 usage for stopping running subagents but does not provide explicit guidance on when to use this tool versus alternatives. It does not mention exclusions, prerequisites, or the recommended workflow, though the schema indicates the handle is required. The context is clear but alternatives are not addressed.

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