Terminate an app

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

No annotations are present, so the description itself must convey behavior. It discloses meaningful behavior beyond the name: the default selection logic (only running non-system app, else only installed app), the ability to override via bundleId or SIM_APP_ID, and the simulator environment. It does not describe failure modes when multiple apps match, but the defaulting logic is clearly stated.

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, information-dense sentence that front-loads the action and environment, then explains the parameter defaulting behavior. There is no filler or repetition.

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 one-parameter tool, the description gives enough context for an agent to invoke it correctly in common cases: target simulator, optional parameter, fallback behavior, and override mechanism. It could mention what happens when no app matches or when multiple apps are running, but this is a minor gap and not likely to block correct use in typical scenarios.

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 only defines 'bundleId' as a string with no description, so the tool description adds needed meaning. It explains that bundleId is optional from the agent's perspective when defaults apply)Skip and that it can also come from an environment variable. The format of a bundle id is not elaborated, but the meaning and optionality are clear.

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 ('terminate') and a clear object ('an app by bundle id on the booted simulator'), so the tool's function is unambiguous. It is distinct from sibling tools like launch_app, open_url, or shutdown_device because it performs a shutdown of an app process.

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 gives clear operating context: it targets apps on the booted simulator and explains the bundleId default behavior, including the fallback from running apps to installed apps. It does not explicitly contrast with alternatives, but the usage context is strong enough to guide the agent.

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