modify_member · Discord MCP: Risk & Policy

WHAT IT DOES

What modify_member does on Discord

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

WHY IT NEEDS A POLICY

Why modify_member needs a policy

This tool creates or modifies data reversibly within a Discord server—it changes member attributes without permanently destroying data. While high-severity due to the potential blast radius (incorrect role assignments or member timeouts could significantly disrupt server operations), it is not Destructive (reversible), Financial, or Execute (no arbitrary code execution).

From the tool's definition modify_member can modify member properties including nickname, roles, and timeout settings. The description explicitly states these are modifications to member properties, which are reversible (roles can be reassigned, nicknames changed back, timeouts…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

modify_member Rate-limited

modify_member 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": {
    "modify_member": {
      "limits": [
        {
          "counter": "modify_member_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 Discord, so you can run agents against it safely.

FAQ

Questions about modify_member

What does the modify_member tool do? +

Modify member properties (nickname, roles, timeout, etc.). It is categorised as a Write tool in the Discord MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on modify_member? +

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

What risk level is modify_member? +

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

Can I rate-limit modify_member? +

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

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

modify_member is provided by the Discord MCP server (scarecr0w12/discord-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.