webview_dom_outlineRetrieve a truncated outerHTML outline of an element inside a mobile WebView to inspect and debug its DOM structure.
取 webview 内某元素(默认 body)的 outerHTML 概要(截断,排错 DOM 结构用)。
| Name | Required | Description | Default |
|---|---|---|---|
| device | Yes | 目标设备 serial(同 mobile_list_available_devices 的 id) | |
| maxChars | No | 截断长度,默认 4000 | |
| selector | No | CSS 选择器,默认 body |
Changes observed during successful MCP inspections.
v0.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already signals a safe read operation, and the description adds behavioral context by disclosing that the output is truncated and that the element defaults to body. It does not cover error behavior or connection prerequisites, but the annotation lowers the burden.
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 one compact sentence with essential behavior front-loaded and no filler. Every part contributes to understanding what the tool does.
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 read-only tool with fully described parametersholistic, the description plus schema is nearly sufficient. The only notable gap is the lack of an output schema or an explicit statement of the return type/format, though 'outerHTML 概要' strongly implies a truncated string.
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 100%, so the schema already documents device, maxChars, and selector. The description adds only domain context, not new parameter details, so the baseline of 3 is appropriate.
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 states a specific verb ('取' / get), a specific resource (outerHTML outline of an element in a webview), and the default target (body). This clearly differentiates it from mobile-screen and other webview sibling tools.
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 explicitly frames the tool for debugging DOM structure ('排错 DOM 结构用'), giving the agent a clear usage context. It does not name alternative tools or when-not conditions, so it stops short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.