List devices

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

No annotations are present, so the description carries the burden of explaining behavior. It clearly states the tool lists devices and returns specific fields (id, platform, name, OS version, state), which sets expectations for output. It does not explicitly assert read-onlyness, but the verb 'list' strongly implies no side effects, and no destructive behavior is hinted.

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, front-loaded with the core action and resource. The first sentence states the purpose and platforms; the second specifies return fields. Every word earns its place, with no redundant phrasing or fluff.

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 no output schema, the description is fully sufficient. It covers the tool's scope (local devices), platforms (Android/iOS), and return fields (id, platform, name, OS version, state). There are no missing parameters or complex side effects to document, so the description is complete for an agent to select and invoke it correctly.

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, and the schema is empty with 100% coverage. The description adds no parameter details, but with no parameters to document, the baseline is 4. It correctly describes the static behavior of returning a list of devices with the specified fields.

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 states the resource ('all available local devices') with clear platform scoping (Android via adb, iOS via simctl). This distinguishes it from sibling tools like device_capabilities, which likely operate on a single device rather than enumerating them.

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 implies the tool is used to discover available local devices and their metadata, but it offers no explicit guidance on when to use it versus alternatives. Since no direct sibling tool provides the same function, the lack of explicit exclusions is acceptable, but the description does not state a recommended context (e.g., before launching an app).

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