create_volume · Hcloud MCP: Risk & Policy

WHAT IT DOES

What create_volume does on Hcloud

AI agents use create_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 create_volume needs a policy

This tool creates a new cloud storage volume, which is a reversible action—volumes can be deleted or modified after creation. It does not execute arbitrary code, delete data irreversibly, or move money. The blast radius is medium because misconfigured volumes could consume resources or expose sensitive data if not properly secured, but the action itself is not inherently destructive or dangerous.

From the tool's definition Tool name 'create_volume' and description 'Create a new volume' indicate the tool creates a new resource (volume) in the Hetzner Cloud infrastructure.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_volume Rate-limited

create_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": {
    "create_volume": {
      "limits": [
        {
          "counter": "create_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 create_volume

What does the create_volume tool do? +

Create a new 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 create_volume? +

Register the Hcloud MCP server in PolicyLayer and add a rule for create_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 create_volume? +

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

Can I rate-limit create_volume? +

Yes. Add a rate_limit block to the create_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 create_volume completely? +

Set action: deny in the PolicyLayer policy for create_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 create_volume? +

create_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.