.Net: Fix mapping of the KernelParameterMetadata.IsRequired property

dotnet/src/SemanticKernel.Abstractions/AI/ChatCompletion/AIFunctionKernelFunction.cs

@@ -66,6 +66,8 @@ private static IReadOnlyList<KernelParameterMetadata> MapParameterMetadata(AIFun
             return Array.Empty<KernelParameterMetadata>();
         }
 
+        HashSet<string>? requiredParameters = GetRequiredParameterNames(aiFunction.JsonSchema);
+
         List<KernelParameterMetadata> kernelParams = [];
         var parameterInfos = aiFunction.UnderlyingMethod?.GetParameters().ToDictionary(p => p.Name!, StringComparer.Ordinal);
         foreach (var param in properties.EnumerateObject())
@@ -76,7 +78,7 @@ private static IReadOnlyList<KernelParameterMetadata> MapParameterMetadata(AIFun
             {
                 Description = param.Value.TryGetProperty("description", out JsonElement description) ? description.GetString() : null,
                 DefaultValue = param.Value.TryGetProperty("default", out JsonElement defaultValue) ? defaultValue : null,
-                IsRequired = param.Value.TryGetProperty("required", out JsonElement required) && required.GetBoolean(),
+                IsRequired = requiredParameters?.Contains(param.Name) ?? false,
                 ParameterType = paramInfo?.ParameterType,
                 Schema = param.Value.TryGetProperty("schema", out JsonElement schema)
                     ? new KernelJsonSchema(schema)
@@ -86,4 +88,25 @@ private static IReadOnlyList<KernelParameterMetadata> MapParameterMetadata(AIFun
 
         return kernelParams;
     }
+
+    /// <summary>
+    /// Gets the names of the required parameters from the AI function's JSON schema.
+    /// </summary>
+    /// <param name="schema">The JSON schema of the AI function.</param>
+    /// <returns>The names of the required parameters.</returns>
+    private static HashSet<string>? GetRequiredParameterNames(JsonElement schema)
+    {
+        HashSet<string>? requiredParameterNames = null;
+
+        if (schema.TryGetProperty("required", out JsonElement requiredElement) && requiredElement.ValueKind == JsonValueKind.Array)
+        {
+            foreach (var node in requiredElement.EnumerateArray())
+            {
+                requiredParameterNames ??= [];
+                requiredParameterNames.Add(node.GetString()!);
+            }
+        }
+
+        return requiredParameterNames;
+    }
 }

dotnet/src/SemanticKernel.UnitTests/AI/ChatCompletion/AIFunctionKernelFunctionTests.cs

@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Linq;
+using Microsoft.Extensions.AI;
+using Microsoft.SemanticKernel;
+using Microsoft.SemanticKernel.ChatCompletion;
+using Xunit;
+
+namespace SemanticKernel.UnitTests.AI.ChatCompletion;
+
+public class AIFunctionKernelFunctionTests
+{
+    [Fact]
+    public void ShouldAssignIsRequiredParameterMetadataPropertyCorrectly()
+    {
+        // Arrange and Act
+        AIFunction aiFunction = AIFunctionFactory.Create((string p1, int? p2 = null) => p1);
+
+        AIFunctionKernelFunction sut = new(aiFunction);
+
+        // Assert
+        KernelParameterMetadata? p1Metadata = sut.Metadata.Parameters.FirstOrDefault(p => p.Name == "p1");
+        Assert.True(p1Metadata?.IsRequired);
+
+        KernelParameterMetadata? p2Metadata = sut.Metadata.Parameters.FirstOrDefault(p => p.Name == "p2");
+        Assert.False(p2Metadata?.IsRequired);
+    }
+}

dotnet/src/SemanticKernel.UnitTests/SemanticKernel.UnitTests.csproj

@@ -24,7 +24,7 @@
     </PackageReference>
     <PackageReference Include="Microsoft.ML.Tokenizers" />
     <PackageReference Include="Microsoft.Extensions.Logging.Console" />
-    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />
+    <PackageReference Include="Microsoft.Extensions.AI" />
   </ItemGroup>
 
   <ItemGroup>