fix(setup): trim trailing hyphens from endpoint names

src/Microsoft.Agents.A365.DevTools.Cli/Commands/CleanupCommand.cs

@@ -776,11 +776,14 @@ private static async Task ExecuteEndpointOnlyCleanupAsync(
             return;
         }
 
+        // Get the actual endpoint name that will be used for deletion (truncated to 42 chars)
+        var endpointName = EndpointHelper.GetEndpointName(config.BotName);
+
         logger.LogInformation("");
         logger.LogInformation("Endpoint Cleanup Preview:");
         logger.LogInformation("============================");
         logger.LogInformation("Will delete messaging endpoint:");
-        logger.LogInformation("  Endpoint Name: {BotName}", config.BotName);
+        logger.LogInformation("  Endpoint Name: {EndpointName}", endpointName);
         logger.LogInformation("  Location: {Location}", config.Location);
         logger.LogInformation("");
 

src/Microsoft.Agents.A365.DevTools.Cli/Services/Helpers/EndpointHelper.cs

@@ -2,16 +2,38 @@
 // Licensed under the MIT License.
 
 using Microsoft.Agents.A365.DevTools.Cli.Constants;
+using Microsoft.Agents.A365.DevTools.Cli.Exceptions;
 
 namespace Microsoft.Agents.A365.DevTools.Cli.Services.Helpers;
 
 public static class EndpointHelper
 {
     public static string GetEndpointName(string name)
     {
-        return name.Length > 42
+        // Validate input
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            throw new SetupValidationException("Endpoint name cannot be null or whitespace.");
+        }
+
+        // Truncate to 42 characters (Azure Bot Service maximum)
+        var truncated = name.Length > 42
             ? name.Substring(0, 42)
             : name;
+
+        // Trim trailing hyphens to comply with Azure Bot Service naming rules
+        // Azure Bot Service does not allow bot names ending with hyphens
+        truncated = truncated.TrimEnd('-');
+
+        // Validate minimum length after trimming
+        if (truncated.Length < 4)
+        {
+            throw new SetupValidationException(
+                $"Endpoint name '{name}' becomes too short after processing (minimum 4 characters required). " +
+                "Please use a longer hostname or provide a custom endpoint name.");
+        }
+
+        return truncated;
     }
 
     /// <summary>

src/Tests/Microsoft.Agents.A365.DevTools.Cli.Tests/Services/Helpers/EndpointHelperTests.cs

@@ -0,0 +1,126 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using FluentAssertions;
+using Microsoft.Agents.A365.DevTools.Cli.Exceptions;
+using Microsoft.Agents.A365.DevTools.Cli.Services.Helpers;
+using Xunit;
+
+namespace Microsoft.Agents.A365.DevTools.Cli.Tests.Services.Helpers;
+
+public class EndpointHelperTests
+{
+    [Fact]
+    public void GetEndpointName_WhenNameIsUnder42Chars_ReturnsOriginalName()
+    {
+        // Arrange
+        var shortName = "my-endpoint";
+
+        // Act
+        var result = EndpointHelper.GetEndpointName(shortName);
+
+        // Assert
+        result.Should().Be("my-endpoint");
+    }
+
+    [Fact]
+    public void GetEndpointName_WhenNameIsExactly42Chars_ReturnsOriginalName()
+    {
+        // Arrange
+        var exactName = "twelve345678901234567890123456789012345678"; // 42 chars
+
+        // Act
+        var result = EndpointHelper.GetEndpointName(exactName);
+
+        // Assert
+        result.Should().Be(exactName);
+        result.Length.Should().Be(42);
+    }
+
+    [Fact]
+    public void GetEndpointName_WhenNameOver42Chars_TruncatesTo42Chars()
+    {
+        // Arrange
+        var longName = "this-is-a-very-long-endpoint-name-that-exceeds-the-limit-of-42-characters";
+
+        // Act
+        var result = EndpointHelper.GetEndpointName(longName);
+
+        // Assert
+        result.Length.Should().Be(42);
+    }
+
+    [Fact]
+    public void GetEndpointName_WhenTruncationEndsWithHyphen_ShouldTrimTrailingHyphen()
+    {
+        // Arrange - Simulates ngrok free domain scenario
+        // Original: distressingly-gnathonic-alonzo.ngrok-free.app
+        // After conversion: distressingly-gnathonic-alonzo-ngrok-free-app-endpoint
+        var longNameEndingWithHyphen = "distressingly-gnathonic-alonzo-ngrok-free-app-endpoint"; // 54 chars
+
+        // Act
+        var result = EndpointHelper.GetEndpointName(longNameEndingWithHyphen);
+
+        // Assert
+        result.Should().Be("distressingly-gnathonic-alonzo-ngrok-free", "should truncate to 42 chars and trim trailing hyphen");
+        result.Length.Should().Be(41);
+        result.Should().NotEndWith("-", "Azure Bot Service does not allow bot names ending with hyphen");
+    }
+
+    [Fact]
+    public void GetEndpointName_WhenTruncationEndsWithMultipleHyphens_ShouldTrimAllTrailingHyphens()
+    {
+        // Arrange - Edge case with multiple trailing hyphens after truncation
+        // Name that when truncated to 42 will end with "---e"
+        var nameWithMultipleHyphens = "some-very-long-endpoint-name-with-hyphens---extra-content-here"; // 63 chars
+
+        // Act
+        var result = EndpointHelper.GetEndpointName(nameWithMultipleHyphens);
+
+        // Assert - truncates to 42: "some-very-long-endpoint-name-with-hyphens-", then trims to "some-very-long-endpoint-name-with-hyphens"
+        result.Should().Be("some-very-long-endpoint-name-with-hyphens");
+        result.Length.Should().Be(41);
+        result.Should().NotEndWith("-", "Should trim all trailing hyphens");
+    }
+
+    [Theory]
+    [InlineData("my-endpoint-name-", "my-endpoint-name")]
+    [InlineData("endpoint--", "endpoint")]
+    [InlineData("test-name---", "test-name")]
+    public void GetEndpointName_WhenInputEndsWithHyphen_ShouldTrimTrailingHyphens(string input, string expected)
+    {
+        // Act
+        var result = EndpointHelper.GetEndpointName(input);
+
+        // Assert
+        result.Should().Be(expected);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void GetEndpointName_WhenInputIsNullOrWhitespace_ShouldThrowSetupValidationException(string? input)
+    {
+        // Act
+        Action act = () => EndpointHelper.GetEndpointName(input!);
+
+        // Assert
+        act.Should().Throw<SetupValidationException>()
+            .WithMessage("*Endpoint name cannot be null or whitespace*");
+    }
+
+    [Fact]
+    public void GetEndpointName_WhenResultBecomesTooShort_ShouldThrowSetupValidationException()
+    {
+        // Arrange - Name that becomes less than 4 chars after trimming hyphens
+        var shortName = "---";
+
+        // Act
+        Action act = () => EndpointHelper.GetEndpointName(shortName);
+
+        // Assert
+        act.Should().Throw<SetupValidationException>()
+            .WithMessage("*becomes too short after processing*");
+    }
+}