save_image · Image Generation MCP Server MCP: Risk & Policy

WHAT IT DOES

What save_image does on Image Generation MCP Server

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

WHY IT NEEDS A POLICY

Why save_image needs a policy

This tool writes data to the filesystem by persisting image files. While not destructive (files can be overwritten or deleted separately), and not dangerous by itself, it has medium severity because uncontrolled file writes could fill disk space, overwrite important files, or create unwanted artifacts.

From the tool's definition Tool name is 'save_image' and description states it saves a 'base64-encoded image to a file', which creates or modifies files on disk.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_image Rate-limited

save_image 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": {
    "save_image": {
      "limits": [
        {
          "counter": "save_image_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 Image Generation MCP Server, so you can run agents against it safely.

FAQ

Questions about save_image

What does the save_image tool do? +

Save a base64-encoded image to a file. It is categorised as a Write tool in the Image Generation 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 save_image? +

Register the Image Generation MCP Server MCP server in PolicyLayer and add a rule for save_image: 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 Image Generation MCP Server. Nothing to install.

What risk level is save_image? +

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

Can I rate-limit save_image? +

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

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

save_image is provided by the Image Generation MCP Server MCP server (marc-shade/image-gen-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.