Capture full-page or element screenshots as PNG/JPEG for visual verification, debugging, or file saving.
Capture a screenshot of the page or a specific element.
| Name | Required | Description | Default |
|---|---|---|---|
| type | No | ||
| saveAs | No | If set, also write the image to this absolute path. | |
| target | No | If set, screenshot just this element (ref or selector). | |
| element | No | ||
| quality | No | ||
| fullPage | No |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure, but it only restates the basic action. It does not describe the return format (e.g., binary image data or path), whether the tool waits for rendering, or any side effects or permissions required.
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 wasted words. However, its extreme brevity borders on under-specification for a tool with six parameters and no annotations.
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 six parameters, no annotations, and no output schema, the description is not complete enough for an agent to invoke the tool confidently. Critical details like default format, quality behavior, fullPage semantics, and return value are missing.
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 only 33% (only saveAs and target have descriptions), and the description does not compensate. It vaguely mentions 'a specific element' but does not clarify the difference between the 'target' and 'element' parameters or explain type, quality, and fullPage options.
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 ('Capture') and resource ('screenshot') and clarifies the scope ('of the page or a specific element'). It clearly distinguishes what the tool does, though it does not explicitly differentiate this from sibling tools like browser_snapshot or browser_find.
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 guidance is provided on when to use this tool versus alternatives such as browser_snapshot or browser_find. It also fails to mention prerequisites like page load state or whether the screenshot captures the viewport by default.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.