docs(config): add examples for config agents

PiperOrigin-RevId: 793871778

contributing/samples/tool_human_in_the_loop/README.md

@@ -0,0 +1,3 @@
+# Config-based Agent Sample - Human-In-The-Loop
+
+http://google3/third_party/py/google/adk/open_source_workspace/contributing/samples/human_in_loop/

contributing/samples/tool_human_in_the_loop/root_agent.yaml

@@ -0,0 +1,17 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/google/adk-python/refs/heads/main/src/google/adk/agents/config_schemas/AgentConfig.json
+name: reimbursement_agent
+model: gemini-2.0-flash
+instruction: |
+  You are an agent whose job is to handle the reimbursement process for
+      the employees. If the amount is less than $100, you will automatically
+      approve the reimbursement.
+
+      If the amount is greater than $100, you will
+      ask for approval from the manager. If the manager approves, you will
+      call reimburse() to reimburse the amount to the employee. If the manager
+      rejects, you will inform the employee of the rejection.
+tools:
+  - name: tool_human_in_the_loop.tools.reimburse
+  - name: LongRunningFunctionTool
+    args:
+      func: tool_human_in_the_loop.tools.ask_for_approval

contributing/samples/tool_human_in_the_loop/tools.py

@@ -0,0 +1,21 @@
+from typing import Any
+
+from google.adk.tools.tool_context import ToolContext
+
+
+def reimburse(purpose: str, amount: float) -> str:
+  """Reimburse the amount of money to the employee."""
+  return {
+      'status': 'ok',
+  }
+
+
+def ask_for_approval(
+    purpose: str, amount: float, tool_context: ToolContext
+) -> dict[str, Any]:
+  """Ask for approval for the reimbursement."""
+  return {
+      'status': 'pending',
+      'amount': amount,
+      'ticketId': 'reimbursement-ticket-001',
+  }