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. It clearly indicates the tool is a read operation (lists devices) and describes the output content (id, model, etc.). It does not mention any side effects, permissions, or error cases (e.g., what happens if no devices are connected), but for a simple list operation, the level of detail is sufficient. A 4 reflects that the description adds value beyond a bare statement like 'List devices'.

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 long: the first states the action and scope, the second details the return value. No extraneous words, front-loaded with the core purpose. It is admirably concise while still being informative.

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?

Given that the tool has zero parameters and no output schema, the description fully explains what the tool does and what it returns. It does not mention edge cases (e.g., no devices connected) or performance implications, but for a simple list operation, these are not essential. The lack of annotations is compensated by the clarity of the description. Score 4 because it is complete enough for reliable use, but could add notes on expected behavior when the list is empty.

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 dimension shifts to 'no parameters needed.' The description does not need to explain parameters. According to the guidelines, 0 params = baseline 4. The description does not add parameter information (none needed), and the schema coverage is 100%, so no penalty.

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's action ('list'), the resource ('connected Android devices and emulators'), and even enumerates the fields returned (id, model, manufacturer, etc.). This uniquely identifies the tool's purpose and distinguishes it from siblings like get_device_info (which likely returns details for a single device) and list_apps (which lists apps).

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 explicitly mentions the scope ('all connected Android devices and emulators') and the return structure. However, it does not specify when to use this tool versus alternatives (e.g., get_device_info for a specific device), nor any prerequisites (e.g., that the server must be running). The absence of guidelines is mitigated by the fact that the tool has no parameters and a well-defined output, making it straightforward.

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