pull_image · Docker MCP Server MCP: Risk & Policy

WHAT IT DOES

What pull_image does on Docker MCP Server

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

WHY IT NEEDS A POLICY

Why pull_image needs a policy

Pulling a Docker image downloads it from a registry and stores it locally. This is a write operation as it creates/modifies local state (adds an image to the local Docker image store). It is reversible (images can be removed), so it doesn't qualify as Destructive. There's no code execution or financial impact. Misuse could involve pulling malicious images or consuming significant disk space/bandwidth.

From the tool's definition Pull a Docker image

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pull_image Rate-limited

pull_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": {
    "pull_image": {
      "limits": [
        {
          "counter": "pull_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 Docker MCP Server, so you can run agents against it safely.

FAQ

Questions about pull_image

What does the pull_image tool do? +

Pull a Docker image. It is categorised as a Write tool in the Docker 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 pull_image? +

Register the Docker MCP Server MCP server in PolicyLayer and add a rule for pull_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 Docker MCP Server. Nothing to install.

What risk level is pull_image? +

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

Can I rate-limit pull_image? +

Yes. Add a rate_limit block to the pull_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 pull_image completely? +

Set action: deny in the PolicyLayer policy for pull_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 pull_image? +

pull_image is provided by the Docker MCP Server MCP server (pnmice/mcp-server-docker). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.