appium_mobile_device_info

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

The readOnlyHint annotation already covers the non-destructive nature, and the description adds useful behavioral context: a single call can retrieve three different kinds of data selected by the action parameter, and it works across iOS and Android. It does not discuss session behavior, but the schema documents sessionId and its default.

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 short, front-loaded sentences with no filler. The main purpose comes first, followed by the selection mechanism and platform compatibility, so every sentence earns its place.

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 simple three-parameter read-only tool, the description is complete. There is no output schema, but the input schema's action enum descriptions already specify what 'info', 'battery', and 'time' return, so an agent has everything it needs to invoke the tool 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?

Schema description coverage is 100%, so the schema already fully explains the action enum values, the format parameter, and sessionId. The description reinforces that action selects which data to retrieve but adds little beyond the schema, fitting the baseline for fully documented parameters.

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 opens with a specific verb and resource: 'Get device information, battery status, or current device time.' It immediately ties these outputs to the action parameterable and clearly distinguishes this read-only device-info tool from the sibling control, text, and element-interaction tools.

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 clearly indicates when to use the tool: whenever the agent needs device info, battery status, or device time, and it notes both iOS and Android are supported. It does not explicitly name alternatives for non-device-info tasks, so it falls short of fully explicit when-not-to-use guidance.

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