device_list

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

With no annotations present, the description carries the behavioral disclosure burden. It states exactly what is listed and over which transports, and 'List' implies a non-mutating read operation, giving the agent a clear expectation of no side effects. It does not mention minor caveats like device authorization/trust prompts, but for a simple enumeration tool this is sufficient.

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 sentence that is front-loaded with the action ('List') and resource, followed by the connection scope. Every word earns its place and there is no fluff or repetition.

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 tool with an output schema, the description provides the essential operational context: what is being listed, how the devices connect, and on which host OS. It is complete enough for an agent to select and invoke it correctly, though it could be slightly stronger with a note about expected return data.

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 baseline of 4 applies. The description adds no parameter-level details, but none are needed; the agent can invoke the tool without 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?

The description uses a specific verb ('List') and a clear resource ('iPhones/iPads connected over USB/Wi-Fi') with a host context. It clearly differentiates from sibling tools like device_list_apps or device_info by focusing on connected devices rather than installed apps or device metadata.

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 makes the tool's purpose obvious but provides no explicit when-to-use or when-not-to-use guidance. It does not name alternatives or conditions, leaving the agent to infer that this is the device-enumeration step from the verb and context alone.

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