>>47952442A good design is one that works in the role they designed for it.
Imagine that I designed a cute Pokémon that is intended to be the cutest Pokémon ever. If everyone loves it then the design is good. On the other hand, if the design were ugly but were intended to be the cutest, then the design failed in its purpose and it's objectively bad.
I will compare Pokémon with chairs. Imagine if you want to design a chair but then when you finish building it you realize that you cannot sit in it. No matter if it looks good, the main purpose was sitting on it, so it's a bad design.
On the other hand, imagine if you want to design the most comfortable chair in the world and you done with great success. No matter the appearance of this chair, you got a good design because your design works.
It's very important to know the behavior and lore of the character to know if the design can play role properly. Appearance never was important in world-building, unless they are their role of course but that's not the Pokémon design philosophy, never was.
