Extract a page element's outerHTML via CSS selector to inspect markup or debug UI, returning up to 100KB from the active or specified tab.
Return the outerHTML of a specific element. Cap 100KB.
| Name | Required | Description | Default |
|---|---|---|---|
| tab_id | No | ||
| selector | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It helpfully discloses a 100KB cap, but omits important traits like error behavior for missing selectors, whether it waits for the element, and how the optional tab_id default is resolved.
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?
Two short sentences with the purpose front-loaded and the size constraint stated second. There is almost no waste, though the two ideas could have been combined more tightly.
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 tool with two parameters, no annotations, and no output schema, the description should explain return shape (it partially does) and how to target a tab. The tab_id semantics and missing-element behavior are absent, leaving gaps an agent must fill by trial.
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 0%, and the description only weakly implies the 'selector' parameter via 'specific element' while never mentioning the 'tab_id' parameter at all. It does not compensate for the undocumented schema.
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 ('Return') and resource ('outerHTML of a specific element'), which is more precise than a generic DOM dump. However, it does not differentiate itself from siblings such as browser_dom, browser_page_text, or browser_wp_html, so an agent must infer the distinction.
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?
No when-to-use guidance is given, no alternatives are named, and no conditions (e.g., prefer this over browser_dom when you only need one element) are stated. The agent is left to guess based on the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.