faber_deploy · Faber MCP Server MCP: Risk & Policy

WHAT IT DOES

What faber_deploy does on Faber MCP Server

AI agents invoke faber_deploy to trigger actions in Faber MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why faber_deploy needs a policy

This tool executes a deployment operation on production infrastructure. While deployments are reversible via rollback, the immediate action is to execute code on remote servers, which is an Execute category action.

From the tool's definition Tool name 'faber_deploy' with description 'Trigger a zero-downtime deployment for an app' indicates execution of a deployment operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

faber_deploy Rate-limited

faber_deploy stays usable, but rate-capped — a runaway agent can't fire it dozens of times 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_deploy": {
      "limits": [
        {
          "counter": "faber_deploy_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-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_deploy

What does the faber_deploy tool do? +

Trigger a zero-downtime deployment for an app. It is categorised as a Execute tool in the Faber MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on faber_deploy? +

Register the Faber MCP Server MCP server in PolicyLayer and add a rule for faber_deploy: 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_deploy? +

faber_deploy is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit faber_deploy? +

Yes. Add a rate_limit block to the faber_deploy 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_deploy completely? +

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

faber_deploy 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.