set_metadata · Rawtherapee MCP: Risk & Policy

WHAT IT DOES

What set_metadata does on Rawtherapee

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

WHY IT NEEDS A POLICY

Why set_metadata needs a policy

Setting metadata on image files is a reversible write operation—it modifies file attributes without destructively deleting data or executing arbitrary code. Severity is medium because metadata changes can affect image organization, copyright info, or processing parameters, but they are not irreversible deletions and typically do not pose immediate security risk unless metadata is used for sensitive purposes (e.g.,…

From the tool's definition Tool name 'set_metadata' indicates modification of image metadata. Context of RawTherapee (RAW photo development tool) confirms this writes metadata to image files. Description is empty, limiting certainty.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_metadata Rate-limited

set_metadata 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": {
    "set_metadata": {
      "limits": [
        {
          "counter": "set_metadata_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 Rawtherapee, so you can run agents against it safely.

FAQ

Questions about set_metadata

What does the set_metadata tool do? +

set_metadata. It is categorised as a Write tool in the Rawtherapee MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_metadata? +

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

What risk level is set_metadata? +

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

Can I rate-limit set_metadata? +

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

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

set_metadata is provided by the Rawtherapee MCP server (lucamarien/rawtherapee-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.