additional question at the start of a swap

Before opening a swap would it be possible to have a question 'Do you have what he/she collects and what he/she wants?'
It might reduce immediately declined swaps.
Thank you

I always look at the coins that the other collector has to offer before making any contact for a possible exchange. This still does not mean that an exchange will take place, as you may not have what your proposed collector wants.
Be prepared for many refusals. I have had more refusals than successful exchanges.
Best of luck with all your future exchanges, successful or not.

This suggestion was made when I had to decline yet another swap.

Hello,
I agree it's a good practice to read what the other users are collect and what they are looking for, before initiating an exchange. However I don't want to enforce this as a mandatory step.