discord_crosspost_message · Discord MCP: Risk & Policy

WHAT IT DOES

What discord_crosspost_message does on Discord

AI agents use discord_crosspost_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 discord_crosspost_message needs a policy

This tool creates a new published state for a message and distributes it to follower servers—a reversible write operation. While it has broadcast scope (multiple servers), the action is not destructive (the original message remains), not code execution, and not financial.

From the tool's definition The tool 'publish (crosspost) a message' modifies message state and distributes it across multiple servers. The description explicitly states it publishes/crossposts messages, which is a reversible content modification action.

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

discord_crosspost_message Rate-limited

discord_crosspost_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": {
    "discord_crosspost_message": {
      "limits": [
        {
          "counter": "discord_crosspost_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 discord_crosspost_message

What does the discord_crosspost_message tool do? +

Publish (crosspost) a message from an Announcement channel to every server that follows it. Only works in announcement channels on a message that has not already been published. Requires the Send Messages permission (and Manage Messages for messages authored by others). Returns a confirmation. 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 discord_crosspost_message? +

Register the Discord MCP server in PolicyLayer and add a rule for discord_crosspost_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 discord_crosspost_message? +

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

Can I rate-limit discord_crosspost_message? +

Yes. Add a rate_limit block to the discord_crosspost_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 discord_crosspost_message completely? +

Set action: deny in the PolicyLayer policy for discord_crosspost_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 discord_crosspost_message? +

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