It seems there is an expectation that restaurants on the French side routinely include a 15% service charge built into their prices. However, this is apparently not always true - an example being Auberge Gourmande in Grand Case who clearly state on their website that a 15% service charge is not included. When we have inquired about "service charges" being included at other Grande Case restaurants, the answer is typically no. It does get confusing to know how to best approach this without ending up leaving 30+% "tip" whenever we dine out.