ui_type_text

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

No annotations are provided, so the description carries the full burden and does well: it explicitly labels the effect STATE_MUTATING and states the focus precondition. Gaps remain on failure behavior when nothing is focused and whether existing text is replaced or appended, which matter for a text-injection tool.

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?

Three short labeled clauses (core action, WHEN TO USE, SIDE EFFECTS, LIMITATIONS) with the verb and target front-loaded. No filler sentences.

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 single-param, no-output-schema tool with no annotations, the description covers purpose, usage, mutation semantics, and precondition. Only the error/lack-of-focus behavior and replace-vs-append semantics are missing.

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?

Only one parameter, and schema description coverage is 100% ('Text to type into the focused element'). The description adds no syntax, escaping, or formatting guidance beyond the schema, so the schema does all the work — baseline 3.

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 ('Type text characters') and resource ('currently focused input or textarea element'), with implementation context (CDP Input domain). It is not confused with ui_keyboard in the description, though it never explicitly distinguishes itself from that close sibling, which also injects input.

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?

'WHEN TO USE' enumerates concrete scenarios (search fields, alert parameters, text inputs), and 'LIMITATIONS' gives the precondition that the target must be focused. It stops short of naming alternatives (e.g., ui_keyboard or ui_evaluate) for cases where focus or text injection differs.

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