fix: improve autonomous mode comments per code review

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffAgentExecutor.cs

@@ -316,8 +316,6 @@ internal sealed class HandoffAgentExecutor :
             // turn by injecting a synthetic user message instead of returning control to the user.
             if (this._options.AutonomousMode && !result.IsHandoffRequested && this._autonomousModeTurnCount < this._options.AutonomousModeTurnLimit)
             {
-                this._autonomousModeTurnCount++;
-
                 ChatMessage autonomousMessage = new(ChatRole.User, this._options.AutonomousModePrompt)
                 {
                     CreatedAt = DateTimeOffset.UtcNow,
@@ -334,6 +332,10 @@ internal sealed class HandoffAgentExecutor :
                     context,
                     cancellationToken).ConfigureAwait(false);
 
+                // Increment only after successfully adding the autonomous message to shared state.
+                // This ensures the counter remains accurate if the state write throws an exception.
+                this._autonomousModeTurnCount++;
+
                 return await this.ContinueTurnAsync(
                     state with { ConversationBookmark = autonomousBookmark },
                     [autonomousMessage],

dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/HandoffAgentExecutorTests.cs

@@ -239,13 +239,12 @@ public class HandoffAgentExecutorTests : AIAgentHostingExecutorTestsBase
     [InlineData(1)]
     [InlineData(2)]
     [InlineData(3)]
-    public async Task Test_HandoffAgentExecutor_AutonomousMode_InvokesAgentUpToTurnLimitPlusOne(int turnLimit)
+    public async Task Test_HandoffAgentExecutor_AutonomousMode_InvokesAgentExactlyOnePlusTurnLimitTimes(int turnLimit)
     {
         // Arrange: agent with many prepared turns; no handoff ever requested; autonomous mode ON
-        // We prepare (turnLimit + 2) turns so that if the implementation over-invokes by one,
-        // TestReplayAgent.Turn will be (turnLimit + 2) rather than the expected (turnLimit + 1).
-        // TestReplayAgent does NOT increment Turn when it runs out of prepared messages, so preparing
-        // exactly (turnLimit + 1) would make an extra invocation silently undetectable.
+        // We prepare (turnLimit + 2) turns to detect off-by-one errors. TestReplayAgent stops
+        // incrementing Turn when prepared messages are exhausted, so preparing exactly (turnLimit + 1)
+        // turns would fail to detect if the implementation invokes the agent one extra time.
         int totalTurns = turnLimit + 2;
         TestReplayAgent agent = new(
             Enumerable.Range(0, totalTurns)