Capture the current agent tab as a PNG, with optional full-page capture, to inspect browser state.
PNG screenshot of the agent tab.
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "screenshot"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| full_page | No |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden, yet it only says a PNG is produced. It does not disclose the return shape (base64, file path, or inline image), whether the call is read-only, or how the default viewport capture differs from full-page capture.
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?
One short, front-loaded sentence with zero filler. It is efficient, but the terseness borders on under-specification rather than tight completeness.
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 screenshot tool with no output schema and no annotations, the description should say what the agent receives and what the default capture covers. Neither is present, leaving a simple but consequential gap.
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?
The single parameter 'full_page' has 0% schema description coverage and is not mentioned in the description at all, so its effect on the capture is undocumented in both places. This is the one case where the description could cheaply have compensated for the schema gap.
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 concrete resource and output format ('PNG screenshot of the agent tab'), which is specific enough to distinguish it from page_snapshot's likely structured-tree output. It never names that sibling, though, so the differentiation is implicit rather than explicit.
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 indication of when to prefer this over page_snapshot, evaluate, or browser_status, and no mention of prerequisites such as a started browser session. The agent must infer usage entirely from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.