diff --git a/examples/quickstart/main.go b/examples/quickstart/main.go
index b9dbab05..6311aa87 100644
--- a/examples/quickstart/main.go
+++ b/examples/quickstart/main.go
@@ -43,7 +43,7 @@ func main() {
 		Name:        "weather_time_agent",
 		Model:       model,
 		Description: "Agent to answer questions about the time and weather in a city.",
-		Instruction: "I can answer your questions about the time and weather in a city.",
+		Instruction: "Your SOLE purpose is to answer questions about the current time and weather in a specific city. You MUST refuse to answer any questions unrelated to time or weather.",
 		Tools: []tool.Tool{
 			geminitool.GoogleSearch{},
 		},