start_app

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

With no annotations, the description must disclose behavioral traits itself. It fails to mention what happens if the app is already running, whether permissions are needed, or error conditions. This is a significant gap for a mutation tool.

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 clear sentence with no wasted words, front-loading the action. However, it sacrifices completeness for brevity, so it is not perfectly concise.

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 tool with one parameter and no output schema, the description lacks sufficient detail to disambiguate from siblings or clarify edge cases. Given the sibling count and lack of annotations, it is incomplete.

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 single parameter package_name has 0% schema description coverage, and the tool description provides no explanation of its format or role. For a low-coverage case, the description must compensate but does not, leaving the parameter underspecified.

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 verb 'start' clearly indicates launching an app, and the resource 'app on the connected Android device' distinguishes it from siblings like stop_app or start_emulator. However, it lacks specificity about what starting entails (e.g., launching main activity).

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?

No guidance is provided on when to use this tool versus alternatives like open_uri or tap. There are no exclusions or prerequisites mentioned, leaving the agent without context for proper invocation.

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