Python: dispatch MCP approval modes by kind in the declarative tool

python/packages/declarative/agent_framework_declarative/_models.py

@@ -806,11 +806,15 @@ def __init__(
         self.serverName = _try_powerfx_eval(serverName)
         self.serverDescription = _try_powerfx_eval(serverDescription)
         if not isinstance(approvalMode, McpServerApprovalMode) and approvalMode is not None:
-            # Handle simplified string format: "always" -> {"kind": "always"}
+            # Handle simplified string format: "always" -> {"kind": "always"}.
+            # Dispatch by kind so specify mode parses into its own subclass with
+            # the tool lists; the base class only carries the kind.
             if isinstance(approvalMode, str):
-                approvalMode = McpServerApprovalMode.from_dict({"kind": approvalMode})
+                approvalMode = agent_schema_dispatch({"kind": approvalMode})
             else:
-                approvalMode = McpServerApprovalMode.from_dict(approvalMode)
+                approvalMode = agent_schema_dispatch(approvalMode)
+            if not isinstance(approvalMode, McpServerApprovalMode):
+                raise ValueError(f"Unsupported approval mode: {approvalMode!r}")
         self.approvalMode = approvalMode
         self.allowedTools = allowedTools or []
         self.url = _try_powerfx_eval(url)

python/packages/declarative/tests/test_declarative_models.py

@@ -765,6 +765,32 @@ def test_mcp_tool_from_dict(self):
         assert tool.kind == "mcp"
         assert isinstance(tool.approvalMode, McpServerApprovalMode)
 
+    def test_mcp_tool_specify_approval_mode_parses_with_tool_lists(self):
+        """The specify mode with its tool lists must parse into its own subclass."""
+        tool = McpTool.from_dict({
+            "name": "mcp_tool",
+            "kind": "mcp",
+            "serverName": "test-server",
+            "approvalMode": {
+                "kind": "specify",
+                "alwaysRequireApprovalTools": ["alpha"],
+                "neverRequireApprovalTools": ["beta"],
+            },
+        })
+        assert isinstance(tool.approvalMode, McpServerToolSpecifyApprovalMode)
+        assert tool.approvalMode.alwaysRequireApprovalTools == ["alpha"]
+        assert tool.approvalMode.neverRequireApprovalTools == ["beta"]
+
+    def test_mcp_tool_simplified_specify_approval_mode_parses(self):
+        """The simplified string form must produce the specify subclass, not the base mode."""
+        tool = McpTool.from_dict({"name": "mcp_tool", "kind": "mcp", "approvalMode": "specify"})
+        assert isinstance(tool.approvalMode, McpServerToolSpecifyApprovalMode)
+
+    def test_mcp_tool_rejects_an_unknown_approval_mode(self):
+        """An unknown approval mode name is rejected instead of parsing as the base mode."""
+        with pytest.raises(ValueError, match="Unsupported approval mode"):
+            McpTool.from_dict({"name": "mcp_tool", "kind": "mcp", "approvalMode": "sometimes"})
+
     def test_mcp_tool_with_simplified_approval_mode(self):
         """Test McpTool with simplified string format for approvalMode."""
         # Test simplified string format: approvalMode: "always"