Capture a screenshot of the current page in a stealth browser, with options for full-page, CSS/device scale, and saving to a file or returning base64.
Take a screenshot. Returns base64 if path is omitted.
| Name | Required | Description | Default |
|---|---|---|---|
| path | No | ||
| scale | No | css = smaller, device-consistent CSS pixels; device = full device-pixel resolution. | |
| fullPage | No |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses that omitting path returns base64, which is useful, but it does not explain what happens when a path is supplied, the output format, or whether the current page/viewport is captured. Partial disclosure only.
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, both informative and free of filler. The core action is front-loaded and the additional return behavior is stated concisely.
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 tool this is minimally acceptable, but with no output schema or annotations it leaves gaps: default fullPage behavior, image format, and the effect of providing a path are not described. An agent could call it correctly but would be guessing on several details.
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 low (33%), so the description must compensate. It adds meaning for 'path' by implying it controls file output versus base64 return, but it does not explain 'fullPage' and relies on the schema for 'scale'. This is adequate but incomplete.
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 clear verb and resource ('Take a screenshot') and adds a useful return-mode detail (base64 when path omitted). It does not explicitly differentiate from similar siblings like browser_snapshot, but the action is specific enough to be understood.
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 given about when to use this tool versus alternatives such as browser_snapshot or browser_get_visible_html. There is no mention of prerequisites, current-page dependence, or exclusion cases.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.