list_devices

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

With no annotations, the description must carry the burden itself; it does disclose that discovery is adb-based and that iOS simulator support is macOS-only, which is valuable context. It does not state read-only nature explicitly or describe the shape of the returned list (device IDs, states, offline 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?

A single front-loaded sentence with no filler; the platform qualifier is placed as a trailing caveat rather than obscuring the main purpose.

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 listing tool with no output schema, the description covers what is enumerated and the platform limitation. Slightly more on the returned entries (e.g., whether offline/unauthorized devices are included) would make it fully complete.

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 the baseline of 4 applies; there is nothing for the description to disambiguate beyond confirming the call is argument-free.

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?

Names a specific verb (lists) and resource (Android devices/emulators via adb, plus booted iOS simulators on macOS), including the platform caveat. It is unambiguous, though it does not need to differentiate from the unrelated screen-capture siblings.

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?

No explicit when-to-use or when-not-to-use guidance; the discovery use case (before capture_screen/compare_screen) is only implied by context. The absence of prerequisites or alternatives keeps it at minimum-viable.

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