How can I run a function in unity (inspector, or new scene view) that would add objects to a scene for artists?

Questions & Answers
1

I am looking to make a tool for my artists so they have the ability to do things to (objects, colors, spawning) etc without being in runtime.

Do I just have to make a Editor script and create the functions in there?

2

Check out Extending the Editor and Custom Editors, that should have what you want.(I may have this wrong as the way you phrased it is difficult to parse.(Specifically with the references to Runtime.))