Type any Unicode text into the focused widget, with newlines as Return, and optionally require the window title/class to match a substring before typing.
Type text into the focused widget. Any Unicode works (Korean, emoji...). Newlines press Return. expect_window: substring of the focused window's title or class; if it doesn't match, nothing is typed.
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | ||
| expect_window | No | ||
| screenshot_after | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations, so the description carries the full burden. It discloses meaningful behavior: Unicode support, that newlines press Return, and that a mismatched expect_window results in no typing at all. It omits prerequisites such as focus requirements, accessibility permissions, and typing speed/delay behavior.
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 tight sentences, front-loaded with the core action, then edge-case behavior. Every sentence adds 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?
For a simple input tool with no output schema, the description covers the main action, Unicode handling, newline semantics, and the guard parameter's failure mode. The undocumented screenshot_after parameter is the notable remaining gap.
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 expect_window in detail (substring match against title or class, with failure mode) and implies text semantics (Unicode, newlines), but the third parameter screenshot_after is never mentioned anywhere.
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+resource ('Type text into the focused widget') and adds scope detail (Unicode, newline handling). It does not differentiate itself from the sibling set_text or key, which an agent must choose between, so it stops short of a 5.
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?
Usage is implied through 'focused widget' and the expect_window guard, but there is no explicit statement of when to prefer this over set_text or key. The conditional 'nothing is typed' clause hints at a safety use case without naming it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.