Last updated: December 25, 2021
The tools you will need to make a mod will depend on the mod you are trying to make. I would recommend reviewing the main Sims 4 Mod Tutorial Database page to figure out where to start before downloading any tools.
MizoreYukii - What is XML Injector & Why its Needed for Some Mods
The Sims 4 Mod Constructor (V4) - Zerbu
BrainBlasted - Injection Tools
MizoreYukii - How to Properly Setup the TDESC Browser