Clicks an Android UI element identified by a selector rather than coordinates. Supports long press, selecting nth match, and specifying target package.
节点级点击（选择器解析，非裸坐标）
| Name | Required | Description | Default |
|---|---|---|---|
| nth | No | ||
| pkg | No | ||
| timeout | No | uia 选择器服务端等待秒数 | |
| selector | Yes | ||
| long_click | No |
Changes observed during successful MCP inspections.
v0.5.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, yet it only notes that resolution is selector-based. It does not disclose what happens on timeout, whether the click waits for the element, or how it interacts with the sibling ui.long_click given the long_click parameter.
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?
It is a single terse parenthetical with no filler, which is efficient. However its brevity stems from under-specification rather than disciplined conciseness, leaving most required context unstated.
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 5-parameter interaction tool with no annotations and no output schema, the description is too thin. It omits selector syntax, behavior on failure, and the meaning of long_click/nth/pkg, none of which are recoverable 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 description coverage is only 20%; selector, nth, pkg, and long_click are undocumented in the schema AND absent from the description. The description adds no parameter meaning beyond the timeout field the schema already covers, so it fails to compensate for the coverage gap.
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 (click) and resource (node/selector), and distinguishes its mechanism from coordinate-based tapping via '非裸坐标'. It clearly separates itself from input.tap-style tools, though it does not name the specific sibling alternative.
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 parenthetical implies you should use this when you have a selector to resolve rather than raw coordinates, which implicitly routes against input.tap. However no explicit when/when-not conditions or named alternatives are given, so usage must be inferred.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.