Manage Harness users, user groups, and service accounts via MCP. List and search users, create and manage user groups for team-based access, create service accounts for API automation, and view available permissions. Use when asked to list users, create a user group, manage service accounts, check who has access, or set up team permissions. Do NOT use for role assignments or resource groups (use manage-roles instead). Trigger phrases: list users, user group, service account, who has access, team permissions, add user to group, create service account.