Must be keychain?
IDL T5 or T7
The Swiss+Tech ones are less likely to do a Houdini from your keyring, but I've not found them as good in use. They're OK, but the IDL ones are better
Mini Tool. Kep your eyes on the sales forums here
How strong do the pliers need to be? Would a Dime or LM Squirt or Style PS cover it?
I Have the IDLs, a pair of Swiss+Tech ones, but ditched the Minitool in favour of the Sideclip. I tend to rely on the pliers tool to cover the Phillips and technician sized flat head requirements too, and the Sideclip beats the Mini hands down in that respect .... and it's lighter
The one that lives on my keys is the Dime. It might not be sturdy enough for everyone's needs, but it's not let me down, and it's been on my keys (or on my person another way) pretty much since they came out