Protein Rest with German Malt?

[BuffaloBeer1]

As I type I am mashing a grain bill that includes 7lbs. of Vienna (U.S.) and 5lbs. of Munich (German). When I picked up the grain at the LHBS I was told I needed to do a protein rest. I do know what that is. However, after doing a lot of reading and talking to some others, I decided not to do a protein rest on this batch. Should I have done one? What are the potential effects of me not doing one? How do I know in the future if I definitely need to do one or not? Thanks for any help.

 

[helibrewer]

It may have benefitted since I think it is moderately-modified but I doubt there is any harm in skipping it.