Gemini Tool Combo: Building a LINE Meetup Helper with Maps Grounding and Places API in a Single API Call

Reference articles: Gemini API tooling updates: context circulation, tool combos and Maps grounding for Gemini 3 Google Places API (New) - searchNearby GitHub: linebot-spot-finder Complete code GitHub (Meeting Helper LINE Bot Spot Finder) Background The combination of LINE Bot + Gemini is already very common. Whether it's using Google Search Grounding to let the model look up real-time information or using Function Calling to let the model call custom logic, they are both mature when used alone. But what if you want to achieve both "map location context" and "query real ratings" in the same question ? Taking restaurant search as an example, the traditional approach usually looks like this: User: "Help me find a hot pot restaurant nearby with a rating of 4 stars or above" Solution A (using only Maps Grounding): Gemini has map context, but the rating information is described by AI itself, and accuracy is not guaranteed. Solution B (using only Places API): You can get real ratings, but th