How to get Functions output and re-use within IF/else Statement

I have function at the bottom of my script which counts for how many tools were used.

Then based on how many tools were used I want to perform different actions.

I can easily check the output of the Function but I struggle to put it into If statement.

var HowManyTools = HowManyTools1();

if (HowManyTools <= 2) {
  Category13();
} else if (HowManyTools >= 6) {
  Category12();
} else(HowManyTools > 2) {
  Category12();
}

function HowManyTools1() {}

How to get Functions output and re-use it within IF Statement?

Tried a few examples from here but to no avail