update_server · Hcloud MCP: Risk & Policy

WHAT IT DOES

What update_server does on Hcloud

AI agents use update_server 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_server needs a policy

This tool creates or modifies data reversibly by updating server metadata. While it affects cloud infrastructure, the changes (name and labels) are non-destructive and can be reverted. The severity is medium because misconfiguration or unauthorized updates could affect service availability or operational clarity, but the blast radius is limited compared to destructive or financial operations.

From the tool's definition Tool description states 'Update a server (name, labels)' — this modifies existing server metadata reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_server Rate-limited

update_server 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_server": {
      "limits": [
        {
          "counter": "update_server_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_server

What does the update_server tool do? +

Update a server (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_server? +

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

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

Can I rate-limit update_server? +

Yes. Add a rate_limit block to the update_server 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_server completely? +

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

update_server 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.