mobile_stop_app

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

Annotations are absent, so the description carries full responsibility for behavioral disclosure. It states 'Stop an app' but does not mention side effects (e.g., forceful termination, data loss), requirements (e.g., permissions), or error conditions. The return value is only 'JSON response from the API', which adds little beyond the output schema. For a mutation-like operation, this is a significant gap.

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 brief and well-organized: a one-line purpose, followed by parameter definitions and a return note. It is not overly verbose and avoids redundancy. However, it could be slightly more structured with a clearer separation of the return behavior, but it remains concise and front-loaded with the core action.

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 has an output schema, so return format is covered elsewhere. However, the description omits critical operational details: what happens if the app is not running, whether the stop is graceful or forced, and any prerequisites. For a two-parameter tool with no annotations, the description is adequate but not complete. The presence of the output schema lowers the bar, yet behavioral context is still missing, so a 3 is appropriate.

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 0%, so the description must compensate. It does: it explains that serialno comes from list_devices and that app_name is a package name (Android/HarmonyOS) or bundle ID (iOS). This provides meaning beyond the bare schema property names and clarifies expected value formats, which is helpful for an agent constructing arguments.

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 clearly states the action ('Stop an app') and identifies the resource via parameters. It is specific enough to distinguish from generic device actions, but it does not explicitly differentiate from the sibling 'mobile_stop_current_app', which stops the currently active app. The verb and resource are clear, but the lack of sibling differentiation keeps it from a 5.

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 mobile_stop_current_app or mobile_launch_app. The description implies use when you have a specific app name, but it does not state exclusions or selection criteria. This is a minimal mention, leaving the agent to infer the appropriate context.

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