Part of the healthy agent criteria is a "Network Connectivity" section, highlighted below. It says “The Agent is healthy if the last connection test was successful within X day”
Do you know what actual test do?
This is calculated based on information in "Inv_AeX_AC_Client_Status" table.
Last agent communication time is the latest event from these three:
Tick time – is based on agent connections to NS server by default performed every 30 minutes.