browser_screenshotCaptures the visible browser viewport as an image without overlaying target boxes or page structure, so agents can inspect exactly what a user sees.
Capture the visible viewport as an image. Target boxes and page structure are not drawn into it.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds a genuinely useful behavioral detail (target boxes and page structure are not rendered), but says nothing about return format, timing, or whether it waits for the page to settle.
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, zero waste, with the core action front-loaded and the caveat immediately after. Nothing redundant with the title or 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?
For a parameterless tool with a self-evident action and read-only annotations, the description covers what is captured. The only remaining gap is the return shape (image payload vs. reference), and with no output schema that would have been a useful addition.
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?
Zero parameters, so the baseline is 4. The description still earns it by making clear the capture is viewport-only with no full-page or element-selector options, telling the agent not to look for such parameters.
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?
Specific verb and resource ('Capture the visible viewport as an image'), and the second sentence clarifies scope by excluding drawn overlays. It implicitly contrasts with browser_page (which surfaces page structure) but never names a sibling.
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?
Usage is only implied: the note that page structure isn't drawn in hints that browser_page should be used for structural/textual inspection, but there is no explicit when-to-use or when-not-to-use guidance among the eight siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.