list_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, but for a zero-parameter read-only listing the risk surface is small. 'List' implies a non-mutating read and 'visible to adb' hints at a live adb-server dependency, yet the description never states the read-only nature, error behavior when no devices exist, or whether it triggers a device scan.

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 short sentence with the resource and the scope qualifier front-loaded; nothing is padded or repeated.

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 trivial no-arg, no-output-schema listing tool the description is nearly sufficient: it says what is enumerated and that emulators are included. The only missing context an agent might want is the adb-server prerequisite and the empty-result case, which are minor for a tool of this complexity.

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, so there are no parameter semantics to explain and the baseline of 4 applies. The description correctly does not invent or imply any arguments.

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?

Specific verb+resource ('List Android devices') with a scope clarifier ('visible to adb, including emulators') that tells the agent what population is returned. It does not explicitly differentiate itself from the sibling device_info, which an agent might reasonably confuse with device enumeration.

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?

Usage is only implied: an agent can infer this is the discovery step before calling per-device tools like device_info, battery, or screenshot. There is no explicit when-to-use statement, no mention of prerequisites (e.g. adb server running), and no routing to alternatives.

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