How often should I water Monadenium ritchei indoors? I currently have it in a small clay pot in a Southwest window. I would like to place it outside for the summer, should it be protected from full sun? Thanks in advance for any advice!

Tofu

It will require very little water (when in doubt: don't water is pretty much the rule for all succulents); if you do take it outside make sure to acclimate it to full sun gradually but ultimately that plant will be happiest in full sun.

I agree.
I have mine in full sun outside over the Summer and at that point I don't worry about too much rain, but I am making sure the plant is never sitting waterlogged, have good drainage.
Comes Fall I bring mine inside here in NJ and that is the time they can rot very easily, if watered at all. I just spray them gently every so often during the indoor season, never flood them.
Mine are in need of repotting for sure, but at least I know they are draining well.

Tofu, it would help if you give us your location please. You can add it to your profile.

Thanks so much for your all your help. I've updated my profile with my location.

Maria