In Chinese culture, practicality and competence are highly esteemed virtues. 利索 (lìsuo) is a common compliment that taps directly into this value system. To be called 利索 is to be recognized for your capability, efficiency, and the clean, effective way you handle tasks. It implies that you don't waste time, you don't make a mess, and you get the job done right. A useful Western comparison is the idea of being “a pro” or “slick,” but with a key difference. “Slick” can sometimes carry a negative connotation of being overly smooth or even deceitful. 利索, however, is almost universally positive and grounded. It's less about style and more about substance and reliable skill. It's the praise a grandmother gives her grandchild for cleaning a room quickly and thoroughly, or what a factory foreman says about his best worker. This term reflects a cultural appreciation for tangible results and skillful execution over mere talk or flashy appearances.
利索 is a very flexible adjective used frequently in daily conversation.
The connotation is always positive, and it's generally used in informal to semi-formal situations.