add_thread_member · Discord MCP: Risk & Policy

WHAT IT DOES

What add_thread_member does on Discord

AI agents use add_thread_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 add_thread_member needs a policy

This tool creates or modifies membership state within a thread, which is a reversible write operation. The action itself has limited blast radius - it grants thread access to a user, which can be undone by removing them. It does not delete data (Destructive), execute arbitrary code (Execute), involve financial transactions (Financial), or trigger external operations (Execute).

From the tool's definition Tool name 'add_thread_member' and description 'Add a member to a thread' indicate a modification operation that adds/assigns a member to a Discord thread.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_thread_member Rate-limited

add_thread_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": {
    "add_thread_member": {
      "limits": [
        {
          "counter": "add_thread_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 add_thread_member

What does the add_thread_member tool do? +

Add a member to a thread. 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 add_thread_member? +

Register the Discord MCP server in PolicyLayer and add a rule for add_thread_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 add_thread_member? +

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

Can I rate-limit add_thread_member? +

Yes. Add a rate_limit block to the add_thread_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 add_thread_member completely? +

Set action: deny in the PolicyLayer policy for add_thread_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 add_thread_member? +

add_thread_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.