AI agents call jellyfin.users_list to retrieve information from Arr Stack without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves user information from Jellyfin without modifying state. While the description is empty, the name pattern is consistent with read operations (compare to sibling tools like 'jellyfin.library_search', 'jellyfin.recent_additions'). The severity is low because user enumeration typically has limited blast radius unless the user list contains highly sensitive information.
From the tool's definition Tool name 'users_list' indicates a query/enumeration operation that retrieves user information. The 'list' suffix strongly suggests read-only retrieval without modification.
Attacks that exploit this kind of access
jellyfin.users_list. It is categorised as a Read tool in the Arr Stack MCP Server, which means it retrieves data without modifying state.
Register the Arr Stack MCP server in PolicyLayer and add a rule for jellyfin.users_list: 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 Arr Stack. Nothing to install.
jellyfin.users_list 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 jellyfin.users_list 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 jellyfin.users_list. 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.
jellyfin.users_list is provided by the Arr Stack MCP server (new-usemame/arr-stack-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →