This record as markdown: /tools/tjnull-ludus-fastmcp/list-range-users.md
What list_range_users does on Ludus FastMCP
AI agents call list_range_users to retrieve information from Ludus FastMCP without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why list_range_users is rated Low
This tool simply enumerates existing users associated with a range. It has no side effects, does not execute code or commands, does not modify data, and does not delete or move resources. The action is purely informational retrieval, which is the definition of a Read operation. Confidence is high because the name and description are clear and unambiguous.
From the tool's definition Tool name 'list_range_users' and description 'List users with access to a range' indicate a query operation that retrieves user access information without modifying, executing, or deleting anything.
Attacks that exploit this kind of access
The rule that runs list_range_users 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 list_range_users, this is the rule to start with:
list_range_users is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Ludus FastMCP, apply this rule, and every list_range_users call is checked against it from then on.
Questions about list_range_users
List users with access to a range. It is categorised as a Read tool in the Ludus FastMCP MCP Server, which means it retrieves data without modifying state.
Register the Ludus Fast MCP server in PolicyLayer and add a rule for list_range_users: 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.
list_range_users is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_range_users 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 list_range_users. 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.
list_range_users 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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