add_image_watermark · Mcp Watermark MCP: Risk & Policy

WHAT IT DOES

What add_image_watermark does on Mcp Watermark

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

WHY IT NEEDS A POLICY

Why add_image_watermark needs a policy

This tool creates or modifies data reversibly by adding a watermark overlay to a PDF. The modification is reversible (the watermark can be removed or the original file recovered), so it falls under Write rather than Destructive.

From the tool's definition The tool 'add_image_watermark' modifies PDF documents by adding an image watermark to all pages. The description states it will 'Add an image watermark to all pages in a PDF file,' which is a modification operation that changes the document's content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_image_watermark Rate-limited

add_image_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_image_watermark": {
      "limits": [
        {
          "counter": "add_image_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 Mcp Watermark, so you can run agents against it safely.

FAQ

Questions about add_image_watermark

What does the add_image_watermark tool do? +

Add an image watermark to all pages in a PDF file. It is categorised as a Write tool in the Mcp Watermark 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_image_watermark? +

Register the Mcp Watermark MCP server in PolicyLayer and add a rule for add_image_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 Mcp Watermark. Nothing to install.

What risk level is add_image_watermark? +

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

Can I rate-limit add_image_watermark? +

Yes. Add a rate_limit block to the add_image_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_image_watermark completely? +

Set action: deny in the PolicyLayer policy for add_image_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_image_watermark? +

add_image_watermark is provided by the Mcp Watermark MCP server (xecho-dev/mcp-watermark). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.