fix(chat): clean up tool output and embedded UX

backend/server/chat/agent_tools.py

@@ -398,7 +398,9 @@ def get_trip_details(user, collection_id: str | None = None):
             }
         }
     except Collection.DoesNotExist:
-        return {"error": "Trip not found"}
+        return {
+            "error": "collection_id is required and must reference a trip you can access"
+        }
     except Exception:
         logger.exception("get_trip_details failed")
         return {"error": "An unexpected error occurred while fetching trip details"}
@@ -598,7 +600,7 @@ def get_weather(user, latitude=None, longitude=None, dates=None):
         dates = dates or []
 
         if not isinstance(dates, list) or not dates:
-            return {"error": "dates must be a non-empty list"}
+            return {"error": "dates is required"}
 
         results = [
             _fetch_temperature_for_date(latitude, longitude, date_value)

backend/server/chat/llm_client.py

@@ -337,7 +337,8 @@ When suggesting places:
 - Group suggestions logically (by area, by type, by day)
 
 When modifying itineraries:
-- Always confirm with the user before adding items
+- Confirm with the user before the first add_to_itinerary action in a conversation
+- After the user clearly approves adding items (for example: "yes", "go ahead", "add them", "just add things there"), stop re-confirming and call add_to_itinerary directly for subsequent additions in that conversation
 - Suggest logical ordering based on geography
 - Consider travel time between locations
 

backend/server/chat/views/__init__.py

@@ -253,6 +253,10 @@ class ChatViewSet(viewsets.ModelViewSet):
                 pass
 
         if collection:
+            context_parts.append(
+                "Collection UUID (use this exact collection_id for get_trip_details and add_to_itinerary): "
+                f"{collection.id}"
+            )
             itinerary_stops = []
             seen_stops = set()
             for location in collection.locations.select_related(