create_host · Defined MCP: Risk & Policy

WHAT IT DOES

What create_host does on Defined

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

WHY IT NEEDS A POLICY

Why create_host needs a policy

Creating hosts in a network infrastructure management system is a reversible write operation that adds new resources to the network. While not destructive or financial, it modifies network state and could enable unauthorized network expansion or lateral movement if misused by an agent. High severity due to infrastructure impact; Write category because host creation is typically reversible (hosts can be removed).

From the tool's definition Tool name 'create_host' combined with server context 'managing Defined Networking infrastructure' and sibling tools like 'add_firewall_rule', 'add_host_tag', 'block_host', and 'create_network' indicate this tool creates new infrastructure resources.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_host Rate-limited

create_host 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_host": {
      "limits": [
        {
          "counter": "create_host_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 Defined, so you can run agents against it safely.

FAQ

Questions about create_host

What does the create_host tool do? +

create_host. It is categorised as a Write tool in the Defined 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_host? +

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

What risk level is create_host? +

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

Can I rate-limit create_host? +

Yes. Add a rate_limit block to the create_host 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_host completely? +

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

create_host is provided by the Defined MCP server (quickvm/defined-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.