clipboard_set · Hermes Computer Use MCP: Risk & Policy

WHAT IT DOES

What clipboard_set does on Hermes Computer Use

AI agents use clipboard_set to create or update resources in Hermes Computer Use — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Hermes Computer Use environment.

WHY IT NEEDS A POLICY

Why clipboard_set needs a policy

This tool modifies the system clipboard by writing text to it, which is a reversible write operation. While it doesn't directly modify persistent data, clipboard manipulation can be misused to inject malicious content, credentials, or commands that will be pasted into sensitive applications. The incomplete description reduces confidence slightly, but the function is unambiguous.

From the tool's definition Tool name 'clipboard_set' with description indicating it 'Put[s] text on the system clipboard'; the description is incomplete but clearly describes a write operation that modifies system state (the clipboard).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

clipboard_set Rate-limited

clipboard_set stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "clipboard_set": {
      "limits": [
        {
          "counter": "clipboard_set_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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 clipboard_set

What does the clipboard_set tool do? +

Put text on the system clipboard (useful when type_text would be too. It is categorised as a Write tool in the Hermes Computer Use MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on clipboard_set? +

Register the Hermes Computer Use MCP server in PolicyLayer and add a rule for clipboard_set: 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 clipboard_set? +

clipboard_set is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit clipboard_set? +

Yes. Add a rate_limit block to the clipboard_set 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 clipboard_set completely? +

Set action: deny in the PolicyLayer policy for clipboard_set. 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 clipboard_set? +

clipboard_set 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.