Launch App [Pro]

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

No annotations are provided, so the description must disclose behavioral traits. It mentions the app starts with its default/main activity, but does not disclose potential side effects (e.g., if the app is already running, it may be brought to foreground) or permissions needed. It does not state that the app must be installed, so this is adequate but not comprehensive.

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 two clear sentences with zero waste. It front-loads the purpose and provides an example and alternative tool reference efficiently.

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 has 2 required parameters, no output schema, and no annotations, the description adequately covers the purpose, usage, and parameter hint. However, it could mention that the app must be installed or the result of a successful launch (e.g., app opened or error). The existence of sibling tools like stop_app and install_app adds context, but the description is still fairly 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?

Schema description coverage is 100% (both parameters are described in the schema), so baseline is 3. The description adds value by explaining the purpose of package_name and giving an example, but does not add extra meaning beyond the schema for device_id.

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 specifies the exact verb (launch), resource (installed application by package name), and scope (default/main activity). It distinguishes itself from siblings like list_apps, stop_app, and install_app by stating that it launches an app by package name.

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 explicitly tells when to use this tool ('Launch an installed application'), and provides a clear alternative for discovering package names ('Use list_apps to discover available package names'). It also gives an example ('com.android.chrome') for clarity.

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