scroll · Hermes Computer Use MCP: Risk & Policy

WHAT IT DOES

What scroll does on Hermes Computer Use

AI agents invoke scroll to trigger actions in Hermes Computer Use. 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.

WHY IT NEEDS A POLICY

Why scroll needs a policy

This tool triggers OS-level mouse scroll wheel actions in a real Chrome browser. It causes external browser interaction (scrolling the viewport), which is a side-effecting browser action that can trigger lazy-loaded content, auto-play media, or other dynamic page behaviors. It fits Execute as it performs browser automation actions whose effects depend on arguments (position and amount).

From the tool's definition Scroll wheel at cursor (or at given x/y if provided). amount = click count.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

scroll Rate-limited

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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "scroll": {
      "limits": [
        {
          "counter": "scroll_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Hermes Computer Use, so you can run agents against it safely.

FAQ

Questions about scroll

What does the scroll tool do? +

Scroll wheel at cursor (or at given x/y if provided). amount = click count. It is categorised as a Execute tool in the Hermes Computer Use MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on scroll? +

Register the Hermes Computer Use MCP server in PolicyLayer and add a rule for 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 Hermes Computer Use. Nothing to install.

What risk level is scroll? +

scroll is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit scroll? +

Yes. Add a rate_limit block to the 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.

How do I block scroll completely? +

Set action: deny in the PolicyLayer policy for 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.

What MCP server provides scroll? +

scroll is provided by the Hermes Computer Use MCP server (noah3521/hermes-computer-use). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.