In the piece I'm editing right now, my client was talking in one sentence about a set of "frameworks," and then in the next sentence she referred to some "tools." It took me about two seconds of puzzling before I realized that "tools" was referring back to the frameworks.
In academic writing, it's usually best to just use the same word for a key concept over and over rather than substituting synonyms.
Although our elementary school teachers insisted that we shouldn't use repetitive vocabulary, that's not necessarily true in academic writing. When the ideas are highly complex, the language shouldn't be.
Every time your reader has to stop and puzzle over what you meant ("are tools the same thing as frameworks?"), she uses a little bit of cognitive energy that should have gone towards understanding your argument.
Clear as many roadblocks as you can for the reader so she can focus on the logic and support and stakes of your argument.