status

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

With no annotations, the description carries the full burden. It explicitly states 'It changes nothing on the phone', providing a crucial non-destructive guarantee. It also enumerates outputs, aiding expectation setting. Missing minor details like behavior on connection failure, but sufficient for a read-only status check.

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?

Three concise sentences, each serving a distinct purpose: purpose, usage guidance, and reported data plus safety. No filler, information is front-loaded and well organized.

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 zero-parameter tool with an output schema, the description covers all essentials: what it does, when to call it, what it returns, and that it's side-effect free. The existing output schema handles detailed return structure, so nothing is missing.

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 has zero parameters, so the description adds no parameter meaning. Following the baseline for 0 parameters, a score of 4 is appropriate; the description doesn't need to elaborate on inputs.

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 tool checks the phone connection and provides current device state. It lists specific information reported (model, Android version, screen size, foreground app, screen state, battery), distinguishing it from sibling tools like read_screen or take_screenshot which focus on UI content.

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?

Explicitly instructs to call this first when a command fails and before any multi-step operation. This gives clear, actionable guidance on when to use the tool, and the non-destructive nature further encourages its use as a diagnostic first step.

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