Type Text

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

With no annotations, the description carries the full burden and discloses a real failure mode (keystrokes sent while the field is opening are lost), the ASCII-only adb limitation, and clear/enter side effects. It does not cover error behavior on an invalid ref or whether `clear` is irreversible, so it falls just short of a 5.

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?

Front-loaded with the core action, then the optional behaviors, then the timing pitfall. Slightly long and the middle clause is a bit run-on, but every sentence conveys actionable information with no filler.

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?

Output schema exists so return values need no explanation; the description instead spends its space on the non-obvious timing hazard and the multi-step focus/wait/type recipe, which is exactly what an agent cannot infer from structured fields.

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 0%, so the description must compensate: it explains ref and text_target as focus targets, clear as clearing the existing value, and enter as pressing Enter after. Only the `device` parameter is left unexplained, which is a modest gap for a 6-parameter tool.

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?

Opens with a specific verb and resource ("Type text into a field") and immediately clarifies its interaction boundary with sibling tools tap, press_key, and snapshot. An agent can distinguish it from tap or press_key without consulting the schema.

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?

Gives an explicit conditional workflow: if tapping the field opens a new screen, tap first, wait with snapshot() or wait_for_text(), then type with no target. It names the alternative tools and the exact conditions that select them, plus the "check the result with snapshot()" follow-up.

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