feat(tools): exposed configurable parameter as property in McpToolset

Merge #4271

**Please ensure you have read the [contribution guide](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) before creating a pull request.**

### Link to Issue or Description of Change

- Closes: #4270

**Problem:**
 When using MCP tools with McpToolset, configuration information for the object is not exposed as object properties or attributes meaning that 'private' attributes need to be accessed, e.g. toolset._connection_params rather than toolset.connection_params

**Solution:**
Exposed them as properties

### Testing Plan

**Unit Tests:**

- [x] I have added or updated unit tests for my change.
- [x] All unit tests pass locally.

**Manual End-to-End (E2E) Tests:**

 I have added new test cases also checked locally

### Checklist

- [x] I have read the [CONTRIBUTING.md](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) document.
- [x] I have performed a self-review of my own code.
- [x] I have commented my code, particularly in hard-to-understand areas.
- [x] I have added tests that prove my fix is effective or that my feature works.
- [x] New and existing unit tests pass locally with my changes.
- [x] I have manually tested my changes end-to-end.
- [x] Any dependent changes have been merged and published in downstream modules.

### Additional context

Co-authored-by: Haran Rajkumar <haranrk@google.com>
COPYBARA_INTEGRATE_REVIEW=#4271 from DineshThumma9:mcp-missing-attr 3d48401
PiperOrigin-RevId: 943396972

Author: 2 people

src/google/adk/tools/mcp_tool/mcp_toolset.py

@@ -286,6 +286,41 @@ def _get_auth_headers(
 
     return headers
 
+  @property
+  def connection_params(self) -> Union[
+      StdioServerParameters,
+      StdioConnectionParams,
+      SseConnectionParams,
+      StreamableHTTPConnectionParams,
+  ]:
+    return self._connection_params
+
+  @property
+  def auth_scheme(self) -> Optional[AuthScheme]:
+    return self._auth_scheme
+
+  @property
+  def auth_credential(self) -> Optional[AuthCredential]:
+    return self._auth_credential
+
+  @property
+  def require_confirmation(self) -> Union[bool, Callable[..., bool]]:
+    return self._require_confirmation
+
+  @property
+  def header_provider(
+      self,
+  ) -> Optional[
+      Callable[
+          [ReadonlyContext], Union[Dict[str, str], Awaitable[Dict[str, str]]]
+      ]
+  ]:
+    return self._header_provider
+
+  @property
+  def errlog(self) -> TextIO:
+    return self._errlog
+
   async def _execute_with_session(
       self,
       coroutine_func: Callable[[Any], Awaitable[T]],

tests/unittests/tools/mcp_tool/test_mcp_toolset.py

@@ -22,6 +22,8 @@
 from unittest.mock import Mock
 
 from fastapi.openapi.models import OAuth2
+from fastapi.openapi.models import OAuthFlowAuthorizationCode
+from fastapi.openapi.models import OAuthFlows
 from google.adk.agents.readonly_context import ReadonlyContext
 from google.adk.auth.auth_credential import AuthCredential
 from google.adk.auth.auth_credential import AuthCredentialTypes
@@ -96,6 +98,69 @@ def test_init_with_use_mcp_resources(self):
     )
     assert toolset._use_mcp_resources is True
 
+  def test_connection_params(self):
+    """Test getting connection params."""
+    toolset = McpToolset(connection_params=self.mock_stdio_params)
+    assert toolset.connection_params == self.mock_stdio_params
+
+  def test_auth_scheme(self):
+    """Test getting auth scheme."""
+    toolset = McpToolset(connection_params=self.mock_stdio_params)
+    assert toolset.auth_scheme is None
+
+  def test_auth_credential(self):
+    """Test getting auth credential."""
+    toolset = McpToolset(connection_params=self.mock_stdio_params)
+    assert toolset.auth_credential is None
+
+  def test_error_log(self):
+    """Test getting error log."""
+    toolset = McpToolset(connection_params=self.mock_stdio_params)
+    assert toolset.errlog == sys.stderr
+
+  def test_auth_scheme_with_value(self):
+    """Test getting auth scheme when provided at initialization."""
+    auth_scheme = OAuth2(
+        flows=OAuthFlows(
+            authorizationCode=OAuthFlowAuthorizationCode(
+                authorizationUrl="https://example.com/auth",
+                tokenUrl="https://example.com/token",
+                scopes={"read": "Read access"},
+            )
+        )
+    )
+    toolset = McpToolset(
+        connection_params=self.mock_stdio_params,
+        auth_scheme=auth_scheme,
+    )
+    assert toolset.auth_scheme == auth_scheme
+
+  def test_require_confirmation(self):
+    """Test getting require_confirmation flag."""
+    toolset = McpToolset(
+        connection_params=self.mock_stdio_params,
+        require_confirmation=True,
+    )
+    assert toolset.require_confirmation is True
+
+  def test_header_provider(self):
+    """Test getting header_provider."""
+    mock_header_provider = Mock()
+    toolset = McpToolset(
+        connection_params=self.mock_stdio_params,
+        header_provider=mock_header_provider,
+    )
+    assert toolset.header_provider == mock_header_provider
+
+  def test_auth_credential_with_value(self):
+    """Test getting auth credential when provided at initialization."""
+    mock_credential = Mock(spec=AuthCredential)
+    toolset = McpToolset(
+        connection_params=self.mock_stdio_params,
+        auth_credential=mock_credential,
+    )
+    assert toolset.auth_credential == mock_credential
+
   def test_init_with_stdio_connection_params(self):
     """Test initialization with StdioConnectionParams."""
     stdio_params = StdioConnectionParams(