Agentless monitoring will not be able to detect the infrastructure of the server. Agentless monitoring only injects into the web page where it gathers performance data from a browser perspective. In order to gather performance data about the infrastructure you will need to install OneAgent on the server.
Hope this helps!
@Santiago B. Agentless monitoring is primarily only used to monitor hosts that cannot be monitored by the oneagent to gain application data. For example, if Easytravel ran on a very old platform, but you wanted to monitor it. You could go with the agentless option. You will gain information at the application level, but not host information like CPU, Memory Etc...