type_text

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

With no annotations, the description carries the burden of behavior. It mentions Unicode support with ADBKeyboard, which is useful, but it does not disclose what happens if no field is focused, whether it clears existing text, or if it performs a tap first. This is a moderate disclosure.

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, concise sentence, front-loading the primary action and including a useful caveat about Unicode support. No filler words; every word 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 2-param tool with full schema coverage, the description is adequate. However, there is no guidance on the focused field requirement or fallback behavior, and no output schema, so an agent might be uncertain about success conditions. It is not missing critical info but could be richer.

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 coverage is 100%, with descriptions for both parameters. The description adds the Unicode detail and the focused input context, but these are not parameter-specific. The schema already explains text and device_id, so the description adds minimal extra param meaning.

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 clearly states it types text into the currently focused input field, which is specific and distinguishes it from tap, swipe, and other input tools. It could be improved by noting that it requires a focused field, but overall it is clear.

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 when to use it (when typing text is needed) but does not explicitly contrast with sibling tools like input_text or webview_input, nor does it provide exclusion conditions (e.g., when text field is not focused). It gives no guidance on when not to use it.

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