Hi Jim,
Below notes may be helpful for queries ,
1365123 - Installation of Diagnostics Agents( check the attachment )
Diagnostics Agent Release Characteristics - pg 22
1473974 - Using the SAP Host Agent Auto Upgrade Feature( check the attachment )
https://websmp204.sap-ag.de/~sapidb/012003146900000135752013E/SAP_Host_Agent_129.pdf
Rg,
Karthik