attach_iso · Hcloud MCP: Risk & Policy

WHAT IT DOES

What attach_iso does on Hcloud

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

WHY IT NEEDS A POLICY

Why attach_iso needs a policy

Attaching an ISO to a server modifies the server's configuration by adding a virtual disk/optical drive. This is a reversible operation (ISOs can be detached), making it a Write action. Misuse could disrupt a running server by attaching an unexpected ISO, but the effect is not irreversible.

From the tool's definition 'Attach an ISO to a server' — attaches/mounts an ISO image to an existing server resource

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

attach_iso Rate-limited

attach_iso 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": {
    "attach_iso": {
      "limits": [
        {
          "counter": "attach_iso_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 Hcloud, so you can run agents against it safely.

FAQ

Questions about attach_iso

What does the attach_iso tool do? +

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

How do I enforce a policy on attach_iso? +

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

What risk level is attach_iso? +

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

Can I rate-limit attach_iso? +

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

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

attach_iso is provided by the Hcloud MCP server (xodus-co/hcloud-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.