resize · Ffmpeg MCP: Risk & Policy

WHAT IT DOES

What resize does on Ffmpeg

AI agents use resize 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 resize needs a policy

The resize tool modifies a video file by changing its resolution/scale. This is a Write operation as it creates or modifies data (the video file). While it overwrites the file, video processing tools typically write to a new output file rather than destructively modifying the original in place, making Write the most appropriate category. The blast radius is medium as it could affect important media files.

From the tool's definition Change video resolution/scale. Specify width and height (-1 for auto aspect ratio).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

resize Rate-limited

resize 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": {
    "resize": {
      "limits": [
        {
          "counter": "resize_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 resize

What does the resize tool do? +

Change video resolution/scale. Specify width and height (-1 for auto aspect ratio). 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 resize? +

Register the Ffmpeg MCP server in PolicyLayer and add a rule for resize: 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 resize? +

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

Can I rate-limit resize? +

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

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

resize 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.