crop · Ffmpeg MCP: Risk & Policy

WHAT IT DOES

What crop does on Ffmpeg

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

WHY IT NEEDS A POLICY

Why crop needs a policy

The crop operation transforms video data in a reversible manner—the original file remains unchanged and the output is a modified version. This fits the Write category (modifies data reversibly) rather than Destructive (irreversible deletion).

From the tool's definition Tool 'crop' modifies video content by changing dimensions and region ('Crop video to a specific region. Specify width, height, and position offset'). This creates a new processed output without permanently destroying the original source file.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

crop Rate-limited

crop 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": {
    "crop": {
      "limits": [
        {
          "counter": "crop_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 Ffmpeg, so you can run agents against it safely.

FAQ

Questions about crop

What does the crop tool do? +

Crop video to a specific region. Specify width, height, and position offset. It is categorised as a Write tool in the Ffmpeg MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on crop? +

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

What risk level is crop? +

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

Can I rate-limit crop? +

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

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

crop is provided by the Ffmpeg MCP server (yuan66-hub/ffmpeg-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.