Check points for a new game mechanic design

From my game development experience, I found that there always had problems while making a new game mechanic design.

Here are the main problems: 

• The mechanic doesn't drive player attention;
• The mechanic doesn't help user retention, drive income, and make surprise;
• The programmer and artists cannot figure out what to do based on the design;
• Cannot work out the UI/UX based on the design;

So check points for different parties:

Producer and Operations:

• Is the mechanic worth to work out? (..  ROI) 
• Can user retention be improved?
• Can it drive income and How much will be?
• Can the new mechanic cohere the main gameplay?

UI & UX:

• Can work out the game flow based on the design?
• How the new mechanics associate with other UIs?
• When will user learn it and How can to learn?

Artist:

• Can the design tell the assets need to produced based?
• Can the assets production meet the deadline?

Programmer:

• Can work out data design based on the game mechanic?
• Can work out program flow based on the game mechanic?
• Is the mechanic contradict itself?
• Is the mechanic too complex so that it is gold plating (over-polish)?
• Can the implementation and testing meet the deadline?