device_status

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

No annotations are provided, so the description carries the full burden. It does disclose the returned signal set, which implies a passive read, but it says nothing about latency, whether it requires a live adb connection, or what happens if the device is offline or locked.

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 front-loaded colon-list with zero filler; every item earns its place as a reported field. It is slightly telegraphic, but nothing is wasted.

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?

With no annotations and no output schema, the description partially compensates by listing the fields it reports, but it omits the response format (flat text vs structured object) and the failure modes for a disconnected or locked device. Adequate but with a clear gap for a diagnostic tool.

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 tool takes zero parameters and the schema is an empty object, so there is nothing for the description to disambiguate. Baseline 4 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 names the resource ('Phone status') and then enumerates the exact facets reported: adb state, Android version, screen on/locked, foreground app, app versions. That is specific enough to separate it from siblings like ui_dump (hierarchy) or device_ls (files), though the verb is implied rather than stated.

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 call this versus alternatives such as ui_dump, ui_find, device_accounts or ui_screenshot, and no preconditions (e.g., whether adb must be connected) are mentioned. The agent must infer usage from the field list alone.

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