Read an Android device's model, Android version, screen size, and currently focused activity to inspect device state before automating actions. Pass a device serial to target one device.
Model, Android version, screen size and the currently focused activity.
| Name | Required | Description | Default |
|---|---|---|---|
| device | No | Device serial from list_devices (omit when exactly one device is connected). |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden. It does reveal the scope of returned data, including the non-obvious 'currently focused activity', which is genuine behavioral content, but it never states that this is a side-effect-free read operation or that it is instantaneous/safe to call repeatedly.
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 compact clause with zero padding; the most informative item (focused activity) is included and nothing is wasted. It loses a point for being a sentence fragment rather than a clear statement of 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?
There is no output schema, so the description usefully compensates by enumerating the returned fields, and the sole optional parameter is fully covered by the schema. It is nearly complete for a simple read tool; only the absence of any usage context keeps it from a 5.
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 100% and the single 'device' parameter is fully documented in the schema, including the omit-when-single-device rule. The description adds nothing about the parameter, so the baseline of 3 applies.
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 is a noun phrase with no verb, so it never states that the tool *retrieves* device information, though that is strongly implied by the name and the listed fields. It enumerates the returned data (model, Android version, screen size, focused activity), which adds content beyond the bare name, but it does not differentiate itself from adjacent info siblings like battery or storage.
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 when-to-use guidance at all — no statement of when an agent should call device_info versus battery, storage, or list_devices. The only implicit cue is that the tool reports device state, which the agent must infer from the field list.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.