android_devices

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It implies a read-only listing operation and explains default-device selection. However, it doesn't describe output format, potential failure modes (e.g., no devices attached), or whether the command can trigger side effects like AVD boot. The description adds some context but omits these details.

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 two sentences with no filler. The first sentence front-loads the action and resource, and the second adds practical usage guidance. Every clause earns its place.

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, no-output-schema discovery tool, the description is largely complete. It covers purpose, default-device behavior, and usage timing. Minor gaps (e.g., what happens when nothing is connected, or whether output includes AVD/device status) are not critical for correct invocation.

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 schema provides nothing to augment. The description compensates by explaining what is listed (physical devices and AVDs) and the default-device logic. This is a reasonable baseline for a parameterless tool, and the added context gives meaning beyond the empty 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 ('List') and resource ('attached Android devices and bootable emulator AVDs'). It also explains the default-device selection logic, distinguishing this tool from siblings like android_emulator_start and android_prepare. The purpose is unambiguous.

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?

The description provides clear guidance: 'Call this first when unsure what is connected.' It also explains how the default device is selected (first physical device, or ANDROID_AGENT_DEVICE if set). While it doesn't explicitly name alternatives or exclusions, this is sufficient for a zero-parameter discovery tool.

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