add_server · MCP Configuration Editor MCP: Risk & Policy

WHAT IT DOES

What add_server does on MCP Configuration Editor

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

WHY IT NEEDS A POLICY

Why add_server needs a policy

This tool creates new configuration entries (adds servers to the MCP configuration), which is reversible data modification. It falls under Write rather than Execute because it only modifies configuration state; the actual execution of added servers would be separate.

From the tool's definition Tool name 'add_server' and description indicating addition of new MCP server configuration. The description (in Japanese) translates to 'Add new MCP server configuration,' which creates a new configuration entry.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_server Rate-limited

add_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": {
    "add_server": {
      "limits": [
        {
          "counter": "add_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 MCP Configuration Editor, so you can run agents against it safely.

FAQ

Questions about add_server

What does the add_server tool do? +

新しいMCPサーバー設定を追加する。. It is categorised as a Write tool in the MCP Configuration Editor MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_server? +

Register the MCP Configuration Editor MCP server in PolicyLayer and add a rule for add_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 MCP Configuration Editor. Nothing to install.

What risk level is add_server? +

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

Can I rate-limit add_server? +

Yes. Add a rate_limit block to the add_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 add_server completely? +

Set action: deny in the PolicyLayer policy for add_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 add_server? +

add_server is provided by the MCP Configuration Editor MCP server (r3-yamauchi/mcp-conf-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.