chore: import upstream snapshot with attribution

contributing/samples/multi_agent/multi_agent_llm_config/README.md

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+# Config-based Agent Sample - LLM multi-agent
+
+From contributing/samples/hello_world_ma/

contributing/samples/multi_agent/multi_agent_llm_config/__init__.py

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+# 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.
+
+import random
+
+from google.adk.examples.example import Example
+from google.adk.tools.example_tool import ExampleTool
+from google.genai import types
+
+
+def roll_die(sides: int) -> int:
+  """Roll a die and return the rolled result."""
+  return random.randint(1, sides)
+
+
+def check_prime(nums: list[int]) -> str:
+  """Check if a given list of numbers are prime."""
+  primes = set()
+  for number in nums:
+    number = int(number)
+    if number <= 1:
+      continue
+    is_prime = True
+    for i in range(2, int(number**0.5) + 1):
+      if number % i == 0:
+        is_prime = False
+        break
+    if is_prime:
+      primes.add(number)
+  return (
+      "No prime numbers found."
+      if not primes
+      else f"{', '.join(str(num) for num in primes)} are prime numbers."
+  )
+
+
+example_tool = ExampleTool(
+    examples=[
+        Example(
+            input=types.UserContent(
+                parts=[types.Part(text="Roll a 6-sided die.")]
+            ),
+            output=[
+                types.ModelContent(
+                    parts=[types.Part(text="I rolled a 4 for you.")]
+                )
+            ],
+        ),
+        Example(
+            input=types.UserContent(
+                parts=[types.Part(text="Is 7 a prime number?")]
+            ),
+            output=[
+                types.ModelContent(
+                    parts=[types.Part(text="Yes, 7 is a prime number.")]
+                )
+            ],
+        ),
+        Example(
+            input=types.UserContent(
+                parts=[
+                    types.Part(
+                        text="Roll a 10-sided die and check if it's prime."
+                    )
+                ]
+            ),
+            output=[
+                types.ModelContent(
+                    parts=[types.Part(text="I rolled an 8 for you.")]
+                ),
+                types.ModelContent(
+                    parts=[types.Part(text="8 is not a prime number.")]
+                ),
+            ],
+        ),
+    ]
+)

contributing/samples/multi_agent/multi_agent_llm_config/prime_agent.yaml

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+# 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.
+
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+agent_class: LlmAgent
+model: gemini-2.5-flash
+name: prime_agent
+description: Handles checking if numbers are prime.
+instruction: |
+  You are responsible for checking whether numbers are prime.
+  When asked to check primes, you must call the check_prime tool with a list of integers.
+  Never attempt to determine prime numbers manually.
+  Return the prime number results to the root agent.
+tools:
+  - name: multi_agent_llm_config.check_prime

contributing/samples/multi_agent/multi_agent_llm_config/roll_agent.yaml

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+# 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.
+
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+agent_class: LlmAgent
+model: gemini-2.5-flash
+name: roll_agent
+description: Handles rolling dice of different sizes.
+instruction: |
+  You are responsible for rolling dice based on the user's request.
+
+  When asked to roll a die, you must call the roll_die tool with the number of sides as an integer.
+tools:
+  - name: multi_agent_llm_config.roll_die

contributing/samples/multi_agent/multi_agent_llm_config/root_agent.yaml

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+# 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.
+
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+agent_class: LlmAgent
+model: gemini-2.5-flash
+name: root_agent
+description: Coordinator agent to greet users.
+# global_instruction: You are DicePrimeBot, ready to roll dice and check prime numbers.
+instruction: |
+  You are a helpful assistant that can roll dice and check if numbers are prime.
+
+  You delegate rolling dice tasks to the roll_agent and prime checking tasks to the prime_agent.
+
+  Follow these steps:
+  1. If the user asks to roll a die, delegate to the roll_agent.
+  2. If the user asks to check primes, delegate to the prime_agent.
+  3. If the user asks to roll a die and then check if the result is prime, call roll_agent first, then pass the result to prime_agent.
+
+  Always clarify the results before proceeding.
+sub_agents:
+  - config_path: roll_agent.yaml
+  - config_path: prime_agent.yaml
+tools:
+  - name: multi_agent_llm_config.example_tool
+generate_content_config:
+  safety_settings:
+    - category: HARM_CATEGORY_DANGEROUS_CONTENT
+      threshold: 'OFF'