diff --git a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/.editorconfig b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/.editorconfig
index 5e51edaf1..24b8ee970 100644
--- a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/.editorconfig
+++ b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/.editorconfig
@@ -2,3 +2,6 @@
 
 # CS0618: Type or member is obsolete
 dotnet_diagnostic.CS0618.severity = silent
+
+# IDE0028: Simplify collection initialization
+dotnet_diagnostic.IDE0028.severity = silent
diff --git a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/SequenceBuilder.cs b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/SequenceBuilder.cs
index 17105b53a..979105d67 100644
--- a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/SequenceBuilder.cs
+++ b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/SequenceBuilder.cs
@@ -3,10 +3,10 @@
 
 namespace Microsoft.Teams.AI.AI.Models
 {
-    public class SequenceBuilder<T>
+    internal class SequenceBuilder<T>
     {
-        private Segment _first;
-        private Segment _last;
+        private Segment? _first;
+        private Segment? _last;
 
         public void Append(ReadOnlyMemory<T> data)
         {
diff --git a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/StreamingChatToolCallsBuilder.cs b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/StreamingChatToolCallsBuilder.cs
index 80f10c10f..78b1f23b7 100644
--- a/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/StreamingChatToolCallsBuilder.cs
+++ b/dotnet/packages/Microsoft.TeamsAI/Microsoft.TeamsAI/AI/Models/StreamingChatToolCallsBuilder.cs
@@ -3,11 +3,11 @@
 
 namespace Microsoft.Teams.AI.AI.Models
 {
-    public class StreamingChatToolCallsBuilder
+    internal class StreamingChatToolCallsBuilder
     {
-        private readonly Dictionary<int, string> _indexToToolCallId = [];
-        private readonly Dictionary<int, string> _indexToFunctionName = [];
-        private readonly Dictionary<int, SequenceBuilder<byte>> _indexToFunctionArguments = [];
+        private readonly Dictionary<int, string> _indexToToolCallId = new();
+        private readonly Dictionary<int, string> _indexToFunctionName = new();
+        private readonly Dictionary<int, SequenceBuilder<byte>> _indexToFunctionArguments = new();
 
         public void Append(StreamingChatToolCallUpdate toolCallUpdate)
         {
@@ -39,7 +39,7 @@ public void Append(StreamingChatToolCallUpdate toolCallUpdate)
 
         public IReadOnlyList<ChatToolCall> Build()
         {
-            List<ChatToolCall> toolCalls = [];
+            List<ChatToolCall> toolCalls = new();
 
             foreach (KeyValuePair<int, string> indexToToolCallIdPair in _indexToToolCallId)
             {