chore: import upstream snapshot with attribution

contributing/samples/tools/function_tools/agent.py

@@ -0,0 +1,58 @@
+# Copyright 2026 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 __future__ import annotations
+
+import os
+import random
+
+from google.adk.agents import Agent
+
+_counter = 0
+
+
+def generate_random_number(max_value: int = 100) -> int:
+  """Generates a random integer between 0 and max_value (inclusive).
+
+  Args:
+      max_value: The upper limit for the random number.
+
+  Returns:
+      A random integer between 0 and max_value.
+  """
+  # Return a growing value in tests to ensure determinism while allowing
+  # multiple calls.
+  if "PYTEST_CURRENT_TEST" in os.environ:
+    global _counter
+    _counter += 1
+    return _counter
+  return random.randint(0, max_value)
+
+
+def is_even(number: int) -> bool:
+  """Checks if a given number is even.
+
+  Args:
+      number: The number to check.
+
+  Returns:
+      True if the number is even, False otherwise.
+  """
+  return number % 2 == 0
+
+
+root_agent = Agent(
+    name="function_tools",
+    tools=[generate_random_number, is_even],
+)