set_group_icon · Bluebubbles MCP: Risk & Policy

WHAT IT DOES

What set_group_icon does on Bluebubbles

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

WHY IT NEEDS A POLICY

Why set_group_icon needs a policy

This tool creates or modifies data (the group icon) in a reversible manner. It does not delete or destroy data (Destructive), execute arbitrary code (Execute), involve financial transactions (Financial), or retrieve data without side effects (Read).

From the tool's definition Tool description states 'Set a group chat's icon', which modifies group chat metadata. The verb 'set' indicates a reversible change to chat configuration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_group_icon Rate-limited

set_group_icon 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": {
    "set_group_icon": {
      "limits": [
        {
          "counter": "set_group_icon_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 Bluebubbles, so you can run agents against it safely.

FAQ

Questions about set_group_icon

What does the set_group_icon tool do? +

Set a group chat's icon from base64-encoded image data. It is categorised as a Write tool in the Bluebubbles MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_group_icon? +

Register the Bluebubbles MCP server in PolicyLayer and add a rule for set_group_icon: 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 Bluebubbles. Nothing to install.

What risk level is set_group_icon? +

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

Can I rate-limit set_group_icon? +

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

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

set_group_icon is provided by the Bluebubbles MCP server (metaember/bluebubbles-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.