Can you post a code example showing what you mean? I am not following. When you call an existing function you don't use curly brackets, you use round brackets for the parameter list. You do have curly brackets when you write a function body.
As a very simple test, using C#, VS2017 and VA 2283.2, I added the following code to a function:
string testName;
testName.GetHashCode();
when I accepted the "GetHashCode" function from the listbox, the round brackets were added to the function call automatically.