Scroll page via JS. Returns new scroll position.
AI agents invoke lightweight_scroll to trigger actions in OpenChrome. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
The tool executes JavaScript to scroll the page, which is a browser action with side effects (changing scroll position, potentially triggering scroll-based events like lazy loading or infinite scroll). This falls under Execute as it runs code/browser actions rather than purely reading data.
From the tool's definition Scroll page via JS — executes JavaScript in the browser to manipulate page state
Documented attack patterns abuse exactly the kind of access lightweight_scroll gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OpenChrome, and nothing reaches the server without passing your rules. This is the rule we recommend for lightweight_scroll:
{
"version": "1",
"default": "deny",
"tools": {
"lightweight_scroll": {
"limits": [
{
"counter": "lightweight_scroll_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}lightweight_scroll stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Scroll page via JS. Returns new scroll position. It is categorised as a Execute tool in the OpenChrome MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the OpenChrome MCP server in PolicyLayer and add a rule for lightweight_scroll: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches OpenChrome. Nothing to install.
lightweight_scroll is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the lightweight_scroll rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for lightweight_scroll. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
lightweight_scroll is provided by the OpenChrome MCP server (shaun0927/openchrome). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 106 OpenChrome tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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106 OpenChrome tools catalogued and risk-classified — across an index of 42,500+ MCP servers.