chore: add toolbox sample agent

PiperOrigin-RevId: 759746416

contributing/samples/toolbox_agent/agent.py

@@ -0,0 +1,28 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from google.adk.agents import Agent
+from google.adk.tools import ToolboxToolset
+
+root_agent = Agent(
+    model="gemini-2.0-flash",
+    name="root_agent",
+    instruction="You are a helpful assistant",
+    # Add Toolbox tools to ADK agent
+    tools=[
+        ToolboxToolset(
+            server_url="http://127.0.0.1:5000", toolset_name="my-toolset"
+        )
+    ],
+)