Launch app

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It discloses one important behavior: the launcher activity is resolved automatically. However, it does not mention what happens if the app is not installed, whether the call blocks until the app starts, or what the tool returns. This is a partial disclosure but insufficient for fully understanding the tool's behavior.

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 of 13 words, with no redundant information. It is front-loaded with the main verb and object, making it easy to scan.

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 launch operation, the description captures the core behavior, but it lacks context on prerequisites (app installation), error handling, and return values. The absence of annotations and an output schema means the description should provide more detail to fully inform the agent. It is adequate but not comprehensive.

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 provides descriptions for both appId and serial (100% coverage). The description adds semantic value by clarifying that appId is sufficient to launch the app and that the launcher activity is auto-resolved, so the agent doesn't need to provide an activity parameter. It does not, however, explain the serial parameter beyond what the schema says.

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 verb 'launch' and clearly identifies the resource ('app') and the key parameter ('application id'). It also differentiates from sibling tools like install_app and stop_app by specifying that launcher activity is resolved automatically. This is a clear, specific purpose statement.

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 this tool is used to start an app on a device, but it does not specify when to use it versus alternative tools such as build_run or test_app. No prerequisites (e.g., app must be installed) or exclusions are mentioned. The only usage hint is 'resolves the launcher activity automatically,' which tells the agent it doesn't need to provide an activity name.

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