docs(config): add examples for config agents

PiperOrigin-RevId: 793871778

contributing/samples/tool_agent_tool/root_agent.yaml

@@ -0,0 +1,19 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+name: research_assistant_agent
+model: gemini-2.0-flash
+description: 'research assistant agent that can perform web search and summarize the results.'
+instruction: |
+  You can perform web search and summarize the results.
+  You should always use the web_search_agent to get the latest information.
+  You should always use the summarizer_agent to summarize the results.
+tools:
+  - name: AgentTool
+    args:
+      agent:
+        config_path: ./web_search_agent.yaml
+      skip_summarization: False
+  - name: AgentTool
+    args:
+      agent:
+        config_path: ./summarizer_agent.yaml
+      skip_summarization: False

contributing/samples/tool_agent_tool/summarizer_agent.yaml

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+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+name: summarizer_agent
+model: gemini-2.0-flash
+description: 'summarizer agent that can summarize text.'
+instruction: "Given a text, summarize it."

contributing/samples/tool_agent_tool/web_search_agent.yaml

@@ -0,0 +1,7 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+name: web_search_agent
+model: gemini-2.0-flash
+description: 'an agent whose job it is to perform web search and return the results.'
+instruction: You are an agent whose job is to perform web search and return the results.
+tools:
+  - name: google_search