Can someone give me a high-level overview on what the process is for building a new tool in adobe Illustrator? If it's even possible.
As an example:
App Builder is for building extensibility solutions for Experience Cloud and does not at this time support Creative Cloud products.
To build a plugin for Illustrator, you would need to use CEP. You can find more details here: https://github.com/Adobe-CEP/CEP-Resources