screenlog_drivers · Yaver MCP: Risk & Policy

WHAT IT DOES

What screenlog_drivers does on Yaver

AI agents invoke screenlog_drivers to trigger actions in Yaver. 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 screenlog_drivers needs a policy

screenlog_drivers triggers real processes with real consequences. An agent gone sideways doesn't fire it once — it starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

screenlog_drivers Rate-limited

screenlog_drivers 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": {
    "screenlog_drivers": {
      "limits": [
        {
          "counter": "screenlog_drivers_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 Yaver, so you can run agents against it safely.

FAQ

Questions about screenlog_drivers

What does the screenlog_drivers tool do? +

Report whether local screen-frame capture works on this host and which driver is used (macOS screencapture / Linux scrot-or-gnome / Windows PowerShell / WSL→Windows interop). Run before screenlog_start to confirm capture is possible. It is categorised as a Execute tool in the Yaver MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on screenlog_drivers? +

Register the Yaver MCP server in PolicyLayer and add a rule for screenlog_drivers: 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 Yaver. Nothing to install.

What risk level is screenlog_drivers? +

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

Can I rate-limit screenlog_drivers? +

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

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

screenlog_drivers is provided by the Yaver MCP server (yaver-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.