detach_volume · Hcloud MCP: Risk & Policy

WHAT IT DOES

What detach_volume does on Hcloud

AI agents use detach_volume 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 detach_volume needs a policy

Detaching a volume removes it from a server but does not delete or destroy it. The data on the volume is preserved and the volume can be reattached, making this a reversible Write operation rather than Destructive. However, it can disrupt running workloads if the volume is in use, warranting medium severity.

From the tool's definition 'Detach a volume' - detaching a volume from a server is a reversible operation; the volume and its data remain intact and can be reattached

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

detach_volume Rate-limited

detach_volume 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": {
    "detach_volume": {
      "limits": [
        {
          "counter": "detach_volume_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 detach_volume

What does the detach_volume tool do? +

Detach a volume. 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 detach_volume? +

Register the Hcloud MCP server in PolicyLayer and add a rule for detach_volume: 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 detach_volume? +

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

Can I rate-limit detach_volume? +

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

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

detach_volume 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.