One of the tools I use to help me is "words" readability scale. After doing a spell check, a screen pops up that gives you information about whether or not the writing is easy to read.
Sentence Complexity/Words per sentence(avg.) gives you the length of the sentence. The lower the number, the easier the writing is to read.
"The judgmental narrator subposition infuriated the commando."
Seven words it should be easy.
The words you use can make it difficult to read too.
This is where Flesch Reading Ease and Flesch-Kincaid level can help. These two number can help you see how easy what you've written can be understood.
Learning to use this can help you understand where you maybe losing your readers.
Also, there is a free software program that you can use that gives you a lot of information about your writing.
Try it out at
Have an awesome day,