Launch App

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

Annotations already convey that the operation is not read-only and is not destructive. The description adds little behavioral context beyond the basic act of launching, so it earns a middle score rather than higher.

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?

Two short sentences with no filler. The main action is front-loaded, and the supporting guidance about package name discovery is efficiently placed.

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 description is adequate for a simple launch operation, and all parameters are documented in the schema. However, it references 'list_apps_on_device' while the actual sibling is 'mobile_list_apps', which could mislead an agent attempting to follow the guidance.

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%, establishing a baseline of 3. The description adds value by telling the agent how to discover the packageName parameter's value via a list-apps call, going 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 states a specific verb-resource pair: 'Launch an app on mobile device' and clarifies it means opening a specific app. It is clear, but it does not explicitly distinguish itself from sibling tools like mobile_open_url or mobile_terminate_app.

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?

'Use this to open a specific app' gives a clear condition for use, and the pointer to list apps for finding the package name offers useful context. It does not explicitly state when not to use this tool or name alternative launch mechanisms.

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