trim · Ffmpeg MCP: Risk & Policy

WHAT IT DOES

What trim does on Ffmpeg

AI agents use trim 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 trim needs a policy

This tool creates a new trimmed media file from an existing one. It modifies/produces media content but does not irreversibly destroy the original file — it's a non-destructive edit that outputs a new segment. This places it in the Write category. Severity is medium because misuse could produce unwanted files or overwrite outputs, but the original source is typically preserved.

From the tool's definition Cut/trim a segment from media file by specifying start time and end time or duration. Uses stream copy (fast, no re-encoding).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

trim Rate-limited

trim 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": {
    "trim": {
      "limits": [
        {
          "counter": "trim_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 trim

What does the trim tool do? +

Cut/trim a segment from media file by specifying start time and end time or duration. Uses stream copy (fast, no re-encoding). 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 trim? +

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

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

Can I rate-limit trim? +

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

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

trim 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.