router · MCP Registry MCP: Risk & Policy

WHAT IT DOES

What router does on MCP Registry

AI agents invoke router to trigger actions in MCP Registry. 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 router needs a policy

A router that can dispatch to multiple backend services (PostgreSQL, vector search, LLM completions, etc.) effectively enables arbitrary operations across all those systems. Since it can route to write, destructive, financial, or execute-class operations depending on arguments, it must be classified at the highest applicable severity.

From the tool's definition 'Router for all servers' — routes requests to specialized AI services including embeddings, PDF extraction, reranking, vector search, PostgreSQL, LLM completions, markup, and transcription

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

router Rate-limited

router 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": {
    "router": {
      "limits": [
        {
          "counter": "router_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 MCP Registry, so you can run agents against it safely.

FAQ

Questions about router

What does the router tool do? +

Router for all servers. It is categorised as a Execute tool in the MCP Registry MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on router? +

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

What risk level is router? +

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

Can I rate-limit router? +

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

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

router is provided by the MCP Registry MCP server (redmadrobot-rnd/mcp-registry). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.