'Stingy' often suggests a selfish or unreasonable lack of generosity. It can sound critical. Everyone avoided asking the stingy shopkeeper for a discount.
Pro Tip 2/3
Informal Context
'Stingy' is informal and might be inappropriate in formal writing or speeches. During lunch, the students giggled about their stingy principal.
Pro Tip 3/3
Cultural Differences
Perception of stinginess can vary with culture; what's stingy in one might be prudent in another. In his culture, not tipping is considered stingy.