faber_create_domain · Faber MCP Server MCP: Risk & Policy

WHAT IT DOES

What faber_create_domain does on Faber MCP Server

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

WHY IT NEEDS A POLICY

Why faber_create_domain needs a policy

This tool creates new DNS/domain records and provisions SSL certificates, both of which are write operations that modify live infrastructure. While not destructive (the domain could theoretically be removed later), the scope and blast radius are significant — misconfigured domains or SSL could break application accessibility or security.

From the tool's definition Tool description states it will 'Create and assign a domain to an app (includes SSL setup)' — these are irreversible operations that modify infrastructure configuration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

faber_create_domain Rate-limited

faber_create_domain 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": {
    "faber_create_domain": {
      "limits": [
        {
          "counter": "faber_create_domain_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 Faber MCP Server, so you can run agents against it safely.

FAQ

Questions about faber_create_domain

What does the faber_create_domain tool do? +

Create and assign a domain to an app (includes SSL setup). It is categorised as a Write tool in the Faber MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on faber_create_domain? +

Register the Faber MCP Server MCP server in PolicyLayer and add a rule for faber_create_domain: 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 Faber MCP Server. Nothing to install.

What risk level is faber_create_domain? +

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

Can I rate-limit faber_create_domain? +

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

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

faber_create_domain is provided by the Faber MCP Server MCP server (joshtrebilco/faber-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.