Having typed a user-created function's name I would like to be able to see either the concise syntax dropdown available for inbuilt functions (shown below left) or alternatively to be able to see the user-created function's template with
Edit > Make Template (shown below right), as one can also see for inbuilt functions.
All I really want to see are the names of the function argument variable names so I know what to provide and in which order without having to scroll up/down to find the function definition and avoid getting RSI!
Do I have to write documentation for my functions to enable this or can Mathematica show me the argument variable names I have written in the function definition?
(Apologies if this is trivial/has been answered already, I have looked for an answer for quite a while but probably don't know the right keywords to search for.)