push_image · Docker MCP Server MCP: Risk & Policy

WHAT IT DOES

What push_image does on Docker MCP Server

AI agents use push_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 push_image needs a policy

Pushing an image uploads data to a remote Docker registry, which is a write operation with network side effects. It does not delete anything, but misuse could expose sensitive images to public registries or overwrite existing tags, making the blast radius high.

From the tool's definition Push an image to a Docker registry

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

push_image Rate-limited

push_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": {
    "push_image": {
      "limits": [
        {
          "counter": "push_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 push_image

What does the push_image tool do? +

Push an image to a Docker registry. 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 push_image? +

Register the Docker MCP Server MCP server in PolicyLayer and add a rule for push_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 push_image? +

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

Can I rate-limit push_image? +

Yes. Add a rate_limit block to the push_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 push_image completely? +

Set action: deny in the PolicyLayer policy for push_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 push_image? +

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