This record as markdown: /tools/tjnull-ludus-fastmcp/remove-users-from-group.md
What remove_users_from_group does on Ludus FastMCP
AI agents call remove_users_from_group to permanently remove resources in Ludus FastMCP, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why remove_users_from_group is rated Critical
Removing users from a group modifies access control membership. While the underlying user accounts are not deleted, group membership removal is typically not reversible through the same tool and falls under destructive modification of access/authorization structures. Given the cyber range context, removing users from a group could disrupt active security testing scenarios.
From the tool's definition 'Remove users from a group' — the action of removing users from a group is irreversible in that membership is deleted without an undo mechanism implied
Attacks that exploit this kind of access
The rule that runs remove_users_from_group safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Ludus FastMCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For remove_users_from_group, this is the rule to start with:
remove_users_from_group is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Ludus FastMCP, apply this rule, and every remove_users_from_group call is checked against it from then on.
Questions about remove_users_from_group
Remove users from a group. It is categorised as a Destructive tool in the Ludus FastMCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Ludus Fast MCP server in PolicyLayer and add a rule for remove_users_from_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 Ludus FastMCP. Nothing to install.
remove_users_from_group is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the remove_users_from_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.
Set action: deny in the PolicyLayer policy for remove_users_from_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.
remove_users_from_group is provided by the Ludus Fast MCP server (tjnull/ludus-fastmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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