I didn't cover that because I think the criteria changes depending on your role and the type of company you work for. For instance, when I was at a large financial company, it needed to be something that was well established, with solid documentation and with professional support options (so, often this was something along the lines of professional open source). When I was with a consulting company, I was much more open to new frameworks as I might encounter clients using them or they might be suitable for some project.
When I am compiling my weekly update, it ends up being something that appears to have at least some decent documentation and the description sounds both useful and makes sense (you won't believe how many libraries/frameworks I come across that I simply have no idea what they actually do or how they are different).
Anyway, all that is to say, I don't know that there is one set of criteria that works for everyone and it is subjective anyway. Sorry if that sounds like a cop out.