chore: import upstream snapshot with attribution

examples/basic/tools.py

@@ -0,0 +1,36 @@
+import asyncio
+from typing import Annotated
+
+from pydantic import BaseModel, Field
+
+from agents import Agent, Runner, function_tool
+
+
+class Weather(BaseModel):
+    city: str = Field(description="The city name")
+    temperature_range: str = Field(description="The temperature range in Celsius")
+    conditions: str = Field(description="The weather conditions")
+
+
+@function_tool
+def get_weather(city: Annotated[str, "The city to get the weather for"]) -> Weather:
+    """Get the current weather information for a specified city."""
+    print("[debug] get_weather called")
+    return Weather(city=city, temperature_range="14-20C", conditions="Sunny with wind.")
+
+
+agent = Agent(
+    name="Hello world",
+    instructions="You are a helpful agent.",
+    tools=[get_weather],
+)
+
+
+async def main():
+    result = await Runner.run(agent, input="What's the weather in Tokyo?")
+    print(result.final_output)
+    # The weather in Tokyo is sunny.
+
+
+if __name__ == "__main__":
+    asyncio.run(main())