group_update · ArcGIS MCP: Risk & Policy

WHAT IT DOES

What group_update does on ArcGIS MCP

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

WHY IT NEEDS A POLICY

Why group_update needs a policy

The tool updates group information reversibly. While the empty description reduces confidence slightly, 'update' operations in administrative contexts typically modify (Write category) rather than delete or execute arbitrary operations. Severity is medium because unauthorized group updates could affect access controls and user permissions across organizations, though impacts are theoretically reversible.

From the tool's definition Tool name 'group_update' indicates modification of group data in ArcGIS. Description is empty, limiting evidence specificity. Context from server description ('group management') confirms this operates on group entities.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

group_update Rate-limited

group_update 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": {
    "group_update": {
      "limits": [
        {
          "counter": "group_update_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 ArcGIS MCP, so you can run agents against it safely.

FAQ

Questions about group_update

What does the group_update tool do? +

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

How do I enforce a policy on group_update? +

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

What risk level is group_update? +

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

Can I rate-limit group_update? +

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

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

group_update is provided by the ArcGIS MCP server (renemorenow/arcgis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.