Android shutdown

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

Annotations declare destructiveHint=true and readOnlyHint=false, and the description does not contradict that. It adds behavioral detail beyond annotations: it stops the 'private frame source' and insists that physical devices are refused. These specifics give the agent a clearer picture of what will happen, though it doesn't mention side effects like data loss, which are implied by 'power off'.

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 primary action is front-loaded ('Stop the private frame source and power off'), and the exclusion (physical devices) is a single, compact second sentence. Every word 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 one-parameter destructive tool, the description covers the essentials: what it does, that it targets emulators only, and that it refuses physical devices. It could mention that the emulator must be running or that the action is irreversible, but those are predictable from the tool's nature. Given the schema and annotations, it is sufficiently complete.

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 coverage is 100%: the device parameter already has a descriptive text ('Emulator serial to power off, e.g. "emulator-5554" (from android_devices).'). The tool description itself adds no parameter-level information, so with full schema coverage the baseline of 3 is appropriate.

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 the private frame source and power off') and the resource ('an Android emulator'), and explicitly distinguishes from physical devices by saying they are 'always refused'. This is a specific verb+resource pair that separates it from siblings like android_boot or android_devices.

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?

It gives a clear exclusion: physical devices are refused, implying it is for emulators only. This is useful when-to-not-use guidance. However, it does not explicitly name alternative tools or state when to use this instead (e.g., for cleanup after testing). The context is clear from the purpose, so it earns a 4 rather than 3.

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