create_channel_message · Discord MCP: Risk & Policy

WHAT IT DOES

What create_channel_message does on Discord

AI agents use create_channel_message 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 create_channel_message needs a policy

This tool creates new data (a message) in a Discord channel, which is reversible (messages can be deleted). It does not execute arbitrary code, delete data irreversibly, or move money. The severity is medium because an AI agent could spam channels, impersonate users, or flood servers, but the impact is limited to message creation without destructive capability.

From the tool's definition Tool name 'create_channel_message' and description 'Send a text message to a channel' indicate a message creation operation that modifies channel state by adding new content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_channel_message Rate-limited

create_channel_message 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": {
    "create_channel_message": {
      "limits": [
        {
          "counter": "create_channel_message_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 create_channel_message

What does the create_channel_message tool do? +

Send a text message to a channel. 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 create_channel_message? +

Register the Discord MCP server in PolicyLayer and add a rule for create_channel_message: 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 create_channel_message? +

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

Can I rate-limit create_channel_message? +

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

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

create_channel_message is provided by the Discord MCP server (taka392/discord-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.