update_volume · Hcloud MCP: Risk & Policy

WHAT IT DOES

What update_volume does on Hcloud

AI agents use update_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 update_volume needs a policy

This tool modifies existing cloud infrastructure resources (volume metadata) but does not delete, destroy, or execute arbitrary code. Updates to volume names and labels are reversible changes. Severity is high rather than medium because volumes often store critical data in production environments, and unauthorized modifications could disrupt operations or cause confusion about resource identity and organization.

From the tool's definition Tool description explicitly states 'Update a volume (name, labels)' — update is a reversible modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_volume Rate-limited

update_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": {
    "update_volume": {
      "limits": [
        {
          "counter": "update_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 update_volume

What does the update_volume tool do? +

Update a volume (name, labels). 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 update_volume? +

Register the Hcloud MCP server in PolicyLayer and add a rule for update_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 update_volume? +

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

Can I rate-limit update_volume? +

Yes. Add a rate_limit block to the update_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 update_volume completely? +

Set action: deny in the PolicyLayer policy for update_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 update_volume? +

update_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.