List devices

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

readOnlyHint=true already tells the agent this is a safe read. The parenthetical 'adb devices -l' adds real context by implying the familiar adb output shape (serial, state, model/device columns), but nothing is said about what happens with no devices connected or whether the list is cached/live.

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 sentence with no filler; the parenthetical command reference earns its space by hinting at output format.

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 no-parameter read tool with no output schema, the description plus the adb command reference gives an agent enough to invoke it correctly. The only miss is not clarifying the overlap with emulator_list/device_info.

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?

Zero parameters, so the baseline is 4; there is nothing parameter-related for the description to compensate for and it correctly does not invent any.

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?

States a specific verb and resource ('List connected Android devices and running emulators') and even names the underlying command, so the intent is unambiguous. It does not distinguish itself from the sibling emulator_list or device_info, both of which overlap with this territory.

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 statement of when to call this instead of emulator_list (also emulator-focused) or device_info (per-device detail). The agent must infer from the name alone that this is the discovery step before app_launch, adb_shell, or logcat.

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