Agent Bakery - Default Settings and automatic register Agent

Ok this is totally new to me.

When i do the rules and bake the agents, do already installed hosts receive an update with those rules? If so, my problem is already solved an i work with the rules (automatic update ist configured)

Only question, which syntax is used for performance counters
is it like in the config file?

Shown as above in the picture, it doesnt work for me…