runtime_devices

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

The description adds the behavioral note 'without changing app state,' which reinforces the read-only nature but is somewhat redundant with the readOnlyHint annotation. It does not disclose other traits like output format details, though the annotations already cover safety and open-world aspects.

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 a single, efficient sentence with no unnecessary words, front-loading the core purpose clearly.

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 the tool's simplicity (no parameters, read-only annotations, and an output schema), the description adequately conveys the core action. It could mention when to use it, but for a listing tool, the essential information is present.

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 no parameters, so the baseline score is 4. The description does not need to explain any parameters, and the schema coverage is 100% for the empty object.

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?

States a specific verb (List) and resources (adb devices and iOS simulators), making the tool's function unambiguous and easily distinguishable from siblings like runtime_plan.

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?

Offers no guidance on when to use this tool versus alternatives, nor any prerequisites or context. It simply describes what it does without indicating appropriate scenarios or exclusions.

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