device_type

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

With no annotations, the description bears the full burden of behavioral disclosure. It only says 'Type text into the device' and does not explain whether text is appended or replaced, whether an element must be focused, or whether platform-specific behaviors exist. It is minimally honest but lacks meaningful behavioral depth.

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 extremely concise: a single five-word sentence with no filler and the verb front-loaded. It loses points only because the brevity crosses into under-specification, but on a pure conciseness and structure basis it is efficient.

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 tool with three required parameters, no output schema, and no annotations, the description is incomplete. It omits target semantics, return behavior, platform caveats, and the role of the optional verify flag. An agent would need to infer or inspect other tools to know how to 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?

Schema description coverage is only 25%; only the optional 'verify' parameter is documented. The description adds no meaning to 'text', 'deviceId', or 'platform', and does not clarify how these parameters relate to the typing operation. Given the low coverage, the description should compensate but does not.

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 states a specific verb ('Type') and resource ('the device'), making the core action clear. It is distinct from sibling tools like tap_on_element and device_tap because it specifically indicates text input. However, it does not mention any target or modality nuances, so it is clear but not fully differentiating.

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?

There is no guidance on when to use this tool versus alternatives, nor any mention of prerequisites such as a focused text field. The single sentence provides no exclusions, conditions, or relation to similar tools like get_screen_text or device_press_key.

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