fix(tests): update drive thru instructions (#5405)

Author: chenghao-mou

examples/drive-thru/agent.py

@@ -124,6 +124,7 @@ async def order_combo_meal(
             Regular items like a single cheeseburger cannot be made into a meal unless such a combo explicitly exists.
 
             Only call this function once the user has clearly specified both a drink and a sauce — always ask for them if they're missing.
+            Never infer or assume the drink — if the user has not explicitly named a drink, ask for it before calling this tool.
 
             A meal can only be Medium or Large; Small is not an available option.
             Drink and fries sizes can differ (e.g., “large fries but a medium Coke”).
@@ -293,6 +294,7 @@ async def order_regular_item(
             Call this when the user orders **a single item on its own**, not as part of a Combo Meal or Happy Meal.
 
             The customer must provide clear and specific input. For example, item variants such as flavor must **always** be explicitly stated.
+            Never call this tool when size information is still needed — if the item has multiple sizes and the user has not specified one, ask for the size before calling.
 
             The user might say—for example:
             - “Just the cheeseburger, no meal”

examples/drive-thru/database.py

@@ -17,6 +17,9 @@
     "Do not ask again to confirm the size of the drink or fries. This inference is meant to streamline the interaction. \n"
     "If the customer clearly indicates a different size for the fries or drink, respect their preference. \n"
     "\n\n"
+    "Never infer or assume any detail the customer has not explicitly stated — especially the drink for a combo meal. \n"
+    "If a required detail is missing, always ask the customer before calling any tool. \n"
+    "\n\n"
     "Be fast-keep responses short and snappy. \n"
     "Sound human-sprinkle in light vocal pauses like 'Mmh…', 'Let me see…', or 'Alright…' at natural moments-but not too often. \n"
     "Keep everything upbeat and easy to follow. Never overwhelm the customer, don't ask multiple questions at the same time. \n"

examples/frontdesk/frontdesk_agent.py

@@ -107,20 +107,26 @@ async def schedule_appointment(
             )
         except SlotUnavailableError:
             ctx.userdata.slot_unavailable_count += 1
-            get_job_context().tagger.add(
-                "slot:unavailable",
-                metadata={"count": ctx.userdata.slot_unavailable_count},
-            )
+            try:
+                get_job_context().tagger.add(
+                    "slot:unavailable",
+                    metadata={"count": ctx.userdata.slot_unavailable_count},
+                )
+            except RuntimeError:
+                pass
             # exceptions other than ToolError are treated as "An internal error occurred" for the LLM.
             # Tell the LLM this slot isn't available anymore
             raise ToolError("This slot isn't available anymore") from None
 
         local = slot.start_time.astimezone(self.tz)
         ctx.userdata.booked_times.append(local.isoformat())
-        get_job_context().tagger.add(
-            "appointment:booked",
-            metadata={"time": ctx.userdata.booked_times},
-        )
+        try:
+            get_job_context().tagger.add(
+                "appointment:booked",
+                metadata={"time": ctx.userdata.booked_times},
+            )
+        except RuntimeError:
+            pass
         return f"The appointment was successfully scheduled for {local.strftime('%A, %B %d, %Y at %H:%M %Z')}."
 
     @function_tool