What tools for building do you deem necessary? ratchets, dremels, torque allen wrenches?
Large and small allen wrench (for screws).
Large allen wrench (for nuts).
99.9% of the time, that’s all you’ll need.
Dremels are nice but hacksaws work if you can’t afford a dremel. Ratchets aren’t needed. Allen wrenches definitely, and also a large wrench for nuts.
A metal file or grinder is good to have if you are cutting metal, if you don’t want sharp edges on your robot.
Walmart has a nice cordless rechargeable Dremel right now for $20. All you have to buy is the cutoff disks and holder and you are set.
Well, you said tools; so in terms of programming, probably my custom coded robot information display (Neutron), PROS, CLion (from JetBrains), and my PROS Lib 
ANGLE GRINDER!!!
What is a pros lib?
I assume a library or addon for PROS
Yeah, a library of all my tools such as gyro information and handlers, as well as all of the functions I’d use for turning information into an optimized output.
We use ELKIND tools (They are available on the Vex Robotics website, two sizes of pliers, and a ratchet wrench. If you have all of those, you don’t need anything else.
Hacksaw and clamps. Don’t Forget
If you ziptie motors to motor controller a pin snips would be nice
-really good 5/64’s that wont dull, same with 3/32’s
-allen wrenches
-hacksaw/dremel
-vice
-nut driver
-wrench
-zipties
-electrical tape
-files
probably some more I’m forgetting right now
You would be surprised how much our team has used hammers over the years!
ahh hammers. I knew I was forgetting something.
A 6" small chop saw from Harbor Freight. Makes cutting metal a breeze and at nice right angles (mostly). Much less dangerous than a dremel.
Adding to the list, Flexible sanding blocks are sometimes easier than a metal file for aluminum burrs.
A stationary grinding wheel is good but many times sharpens the metal versus eliminating the edges.
I personally use only torx screws, but if you use hex screws, that’s ok. the tools vex sells are ok, but you can buy much better ones at robosource. Here’s what I say is absolutely necessary.
-several screwdrivers of hex or torx in both sizes
-several wrenches from vex
-one or two pairs of flush cuts (cutting zip ties)
-diagonal cutting plyers (mark aluminum to cut by bending)
-two or three long needle nose plyers (hard to access screws or nuts)
-dremel (check local pawn shops to get them on the cheap)
-several cut down Allen keys for hard to reach places
-white lithium grease (use inside motors)
Would white lithium grease work for regular external gears as well? Or does it not make a difference?
Small vise
Hammer
Screwdrivers & Wrenches
Metal and wood saws
Square, measuring tape, scriber and other marking out tools
Vernier calipers