chore: import upstream snapshot with attribution

python/samples/02-agents/tools/function_tool_declaration_only.py

@@ -0,0 +1,80 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import asyncio
+
+from agent_framework import Agent, FunctionTool
+from agent_framework.openai import OpenAIChatClient
+from dotenv import load_dotenv
+
+# Load environment variables from .env file
+load_dotenv()
+
+"""
+Example of how to create a function that only consists of a declaration without an implementation.
+This is useful when you want the agent to use tools that are defined elsewhere or when you want
+to test the agent's ability to reason about tool usage without executing them.
+
+The only difference is that you provide a FunctionTool without a function.
+If you need a input_model, you can still provide that as well.
+"""
+
+
+async def main():
+    function_declaration = FunctionTool(
+        name="get_current_time",
+        description="Get the current time in ISO 8601 format.",
+    )
+
+    agent = Agent(
+        client=OpenAIChatClient(),
+        name="DeclarationOnlyToolAgent",
+        instructions="You are a helpful agent that uses tools.",
+        tools=function_declaration,
+    )
+    query = "What is the current time?"
+    print(f"User: {query}")
+    result = await agent.run(query)
+    print(f"Result: {result.to_json(indent=2)}\n")
+
+
+"""
+Expected result:
+User: What is the current time?
+Result: {
+  "type": "agent_response",
+  "messages": [
+    {
+      "type": "chat_message",
+      "role": {
+        "type": "role",
+        "value": "assistant"
+      },
+      "contents": [
+        {
+          "type": "function_call",
+          "call_id": "call_0flN9rfGLK8LhORy4uMDiRSC",
+          "name": "get_current_time",
+          "arguments": "{}",
+          "fc_id": "fc_0fd5f269955c589f016904c46584348195b84a8736e61248de"
+        }
+      ],
+      "author_name": "DeclarationOnlyToolAgent",
+      "additional_properties": {}
+    }
+  ],
+  "response_id": "resp_0fd5f269955c589f016904c462d5cc819599d28384ba067edc",
+  "created_at": "2025-10-31T15:14:58.000000Z",
+  "usage_details": {
+    "type": "usage_details",
+    "input_token_count": 63,
+    "output_token_count": 145,
+    "total_token_count": 208,
+    "openai.reasoning_tokens": 128
+  },
+  "additional_properties": {}
+}
+"""
+
+
+if __name__ == "__main__":
+    asyncio.run(main())