slack_update_message · Mcp Gmail MCP: Risk & Policy

WHAT IT DOES

What slack_update_message does on Mcp Gmail

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

WHY IT NEEDS A POLICY

Why slack_update_message needs a policy

The tool name suggests updating/modifying a Slack message, which is a reversible Write operation. However, the empty description prevents verification of actual behavior, and the tool appears misclassified on a Gmail server (likely metadata error). If functional, message updates are Write-category with medium severity due to potential for confusion, misinformation, or impersonation via message tampering.

From the tool's definition Tool name 'slack_update_message' indicates modification of existing data (update); description is empty, limiting confidence

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

slack_update_message Rate-limited

slack_update_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": {
    "slack_update_message": {
      "limits": [
        {
          "counter": "slack_update_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 Mcp Gmail, so you can run agents against it safely.

FAQ

Questions about slack_update_message

What does the slack_update_message tool do? +

slack_update_message. It is categorised as a Write tool in the Mcp Gmail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on slack_update_message? +

Register the Mcp Gmail MCP server in PolicyLayer and add a rule for slack_update_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 Mcp Gmail. Nothing to install.

What risk level is slack_update_message? +

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

Can I rate-limit slack_update_message? +

Yes. Add a rate_limit block to the slack_update_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 slack_update_message completely? +

Set action: deny in the PolicyLayer policy for slack_update_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 slack_update_message? +

slack_update_message is provided by the Mcp Gmail MCP server (@monsoft/mcp-gmail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.