I myself am terrible with names, but here are some common sense guidelines:
How distinctive is the name? Can it be easily confused with a similar fictional character or a character in the opposite direction?
If the name is similar to a known character or historical person, it could be beneficial or hindering. Look at how many characters have Shakespearean names for goodness sakes.
Rare names will make the character distinctive, certainly. But also remember where a name comes from. In the world of your story, someone has given the character that name for some reason. No matter how rare a name is, you have to answer, "Who would name their kid Slartybartfast?".
Common given names help the reader identify with the character, especially in a modern piece. "At least his name is normal."
But it is a good idea to google a name before putting it to print. THe name could be common or it could be the name of a Fortune 500 CEO who likes to sue people.