As a designer you must clearly define your requirements for the tools you need and the game. Working with others try to avoid words that leave you with some misgivings, like "should", "I Want", "more or less"
When asking a programmer to create a tool you need to clearly specify how it should work, what will be the input, and what is to be on the output. Of course, do not zagłębiaj in the action of the programmer too deeply. Your task is to determine the required result.
The same applies to the game mechanic. You decide what is to happen when a player performs a specific action. If you do your work inaccurately or leave a different area of manoeuvre, you can be sure that someone who will perform the game item does not follow your mind.