browser_screenshotCapture a current page or full-page screenshot by providing a session ID. Use it to visually verify page state, debug layouts, and record results during parallel browser automation.
Capture a screenshot of the current page.
| Name | Required | Description | Default |
|---|---|---|---|
| fullPage | No | Capture full scrollable page, not just the viewport. | |
| sessionId | Yes |
Changes observed during successful MCP inspections.
v0.1.14Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the action and does not explain what the screenshot output looks like, whether a session must be active, or whether full-page capture affects behavior. There is no mention of return type, side effects, or error conditions.
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 a single front-loaded sentence with no redundant wording. It is appropriately terse, though it lacks useful context that could be added without harming conciseness.
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?
Given no annotations, no output schema, and an undocumented required sessionId parameter, the description is incomplete for an agent to call the tool confidently. It does not explain what the returned screenshot data is, whether the page must be fully loaded, or how the required session is validated.
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 50%, with sessionId completely undocumented. The description adds no meaning for either parameter, and the fullPage parameter is only explained by the schema itself, not by the tool description.
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 action and resource: capturing a screenshot of the current page. It is clear about the tool's core function, though it does not explicitly distinguish itself from siblings like browser_snapshot or browser_get_page_structure.
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 provides no guidance on when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites. The only implied usage is that it captures a screenshot, but no comparison with sibling tools is given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.