add_watermark · FFmpeg Python MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_watermark does on FFmpeg Python MCP Server

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

WHY IT NEEDS A POLICY

Why add_watermark needs a policy

The tool modifies video content by adding a watermark, which is a reversible transformation (the original video still exists, and a new modified version is created). This is a Write operation rather than Execute because the tool has a specific, bounded function (add watermark) rather than arbitrary code execution.

From the tool's definition Tool name 'add_watermark' and description indicates it modifies video by adding a watermark overlay. This creates a new version of the video file with permanent visual modifications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_watermark Rate-limited

add_watermark 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": {
    "add_watermark": {
      "limits": [
        {
          "counter": "add_watermark_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 Python MCP Server, so you can run agents against it safely.

FAQ

Questions about add_watermark

What does the add_watermark tool do? +

为视频添加水印. It is categorised as a Write tool in the FFmpeg Python MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_watermark? +

Register the FFmpeg Python MCP Server MCP server in PolicyLayer and add a rule for add_watermark: 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 Python MCP Server. Nothing to install.

What risk level is add_watermark? +

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

Can I rate-limit add_watermark? +

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

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

add_watermark is provided by the FFmpeg Python MCP Server MCP server (mabh111111/ffmpeg_python_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.