The problem is none of those things are visible where they matter. Sure your function signature might say what “true” means, and what parameter “true” is assign

The problem is none of those things are visible where they matter. Sure your function signature might say what “true” means, and what parameter “true” is assigned to. Your IDE will probably even give you hints as you type. Those won’t show up in code review. They won’t show up in diffs at all if you rename the parameter and change its semantics.