launch_app

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

The annotations declare readOnlyHint=false, so the agent knows it mutates state, but the description adds no behavioral context such as whether the app comes to foreground, what happens if already running, or what errors may occur. With minimal annotations, the description carries burden and falls short.

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?

One concise sentence that front-loads the action and resource, with 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?

The tool is simple and the schema covers parameters, but the description lacks usage guidance and behavioral context, making it minimally viable rather than fully complete. There is no output schema, so return behavior is unclear, but the core purpose is clear.

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 descriptions cover all three parameters (package_name, activity, device_serial) at 100%, so the baseline is 3. The description only restates that activity is optional, adding no additional semantic detail beyond the schema.

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 ('Launch') and resource ('app by package name'), clearly distinguishing it from sibling tools like stop_app and install_apk. It also signals the optional activity component, which differentiates it from basic launchers.

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 the tool is for starting an app, but it does not explicitly state when to use it versus alternatives like start_emulator or open_obs. There are no exclusions or conditions, so usage context is only implicit.

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