discord_add_reaction · MCP-Discord MCP: Risk & Policy

WHAT IT DOES

What discord_add_reaction does on MCP-Discord

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

WHY IT NEEDS A POLICY

Why discord_add_reaction needs a policy

This tool creates new data (a reaction annotation on a message) but the action is reversible (reactions can be removed). It does not delete data, execute code, move money, or produce irreversible effects. It falls clearly into the Write category as a non-destructive data modification. Severity is low because reaction spam or misuse has minimal blast radius—reactions are cosmetic metadata and easily cleaned up.

From the tool's definition Tool description states it 'Adds an emoji reaction to a specific Discord message'. Adding a reaction is a reversible modification of message metadata.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

discord_add_reaction Rate-limited

discord_add_reaction 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_add_reaction": {
      "limits": [
        {
          "counter": "discord_add_reaction_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-Discord, so you can run agents against it safely.

FAQ

Questions about discord_add_reaction

What does the discord_add_reaction tool do? +

Adds an emoji reaction to a specific Discord message. It is categorised as a Write tool in the MCP-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_add_reaction? +

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

What risk level is discord_add_reaction? +

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

Can I rate-limit discord_add_reaction? +

Yes. Add a rate_limit block to the discord_add_reaction 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_add_reaction completely? +

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

discord_add_reaction is provided by the MCP-Discord MCP server (jar285/mcp-discord). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.