Launch app

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

With no annotations, the description carries the full burden, yet it only states that a launch happens and launch time is reported. It doesn't disclose the default force-stop (cold start) side effect exposed by stopFirst, what 'launch time' means, what happens if the package isn't installed, or whether an already-running instance is killed.

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?

A single tight sentence that front-loads the core action and the launcher-activity default. There is no wasted text, though the compression leaves behavioral gaps rather than filling them.

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 four-parameter mutation tool with no annotations and no output schema, the description is minimally viable. It omits device targeting behavior, cold-start semantics, and failure modes, so an agent could call it but would be guessing at side effects.

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 coverage is 100%, so all four parameters, including serial selection and the stopFirst cold-start default, are documented in the schema. The description only echoes the activity-vs-launcher distinction already covered there, so it adds nothing beyond the structured fields.

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 states a specific verb (start) and resource (an app's launcher activity, or a named activity) and notes it reports launch time. It doesn't distinguish itself from nearby siblings like run_app or app_stop, so an agent must infer that this is low-level ADB-style launching rather than a Gradle/IDE run.

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?

There is no guidance on when to use this instead of run_app, app_stop, or input/emulator tools, nor any preconditions such as the app being installed or a device being selected. The agent is left to infer usage entirely.

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