update-group · Sidemail MCP Server MCP: Risk & Policy

WHAT IT DOES

What update-group does on Sidemail MCP Server

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

WHY IT NEEDS A POLICY

Why update-group needs a policy

This tool creates or modifies data in a reversible manner. It updates group settings or membership in Sidemail's Messenger system, which can be changed again. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), or move money (would be Financial). The moderate severity reflects that misuse could alter group configurations affecting multiple users, but the action is reversible.

From the tool's definition Tool name 'update-group' and description explicitly states 'Update a Group', which modifies existing data. Grouped with other write operations like 'create-or-update-contact' and 'create-messenger-draft' on the Sidemail platform.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update-group Rate-limited

update-group 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": {
    "update-group": {
      "limits": [
        {
          "counter": "update-group_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 Sidemail MCP Server, so you can run agents against it safely.

FAQ

Questions about update-group

What does the update-group tool do? +

Update a Group (Sidemail Messenger API). It is categorised as a Write tool in the Sidemail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update-group? +

Register the Sidemail MCP Server MCP server in PolicyLayer and add a rule for update-group: 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 Sidemail MCP Server. Nothing to install.

What risk level is update-group? +

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

Can I rate-limit update-group? +

Yes. Add a rate_limit block to the update-group 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 update-group completely? +

Set action: deny in the PolicyLayer policy for update-group. 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 update-group? +

update-group is provided by the Sidemail MCP Server MCP server (sidemail/sidemail-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.