.Net: New function calling model (#8811)

### Motivation and Context

Today, every AI connector in SK that supports function calling has its
own implementation of tool call behavior model classes. These classes
are used to configure the way connectors advertise and invoke functions.
For example, the behavior classes can describe which functions should be
advertised to AI model by a connector, whether the functions should be
called automatically by the connector, or if the connector caller will
invoke them manually, etc.

All the tool call behavior classes are the same in terms of describing
the desired function call behavior. However, the classes have a mapping
functionality to map the function call behavior to the
connector-specific model classes, and that's what makes the function
calling classes non-reusable between connectors.

Additionally, today, it's not possible to specify function calling
behavior declaratively in YAML and JSON prompts.

### Description

This PR introduces a few function choice behavior classes that allow
configure function calling behavior in connector agnostic way:

- FunctionChoiceBehavior - an abstract class that used as a base class
for all the choice behaviors described below.
- AutoFunctionChoiceBehavior - inherits the FunctionChoiceBehavior class
and contains configuration to tell AI model to decide to choose from
zero or more of the provided function(s) for invocation.
- RequiredFunctionChoiceBehavior - inherits the FunctionChoiceBehavior
class and contains configuration forcing AI model to choose provided
function(s) for invocation.
- NoneFunctionChoiceBehavior - inherits the FunctionChoiceBehavior class
and contains configuration to tell the model not to choose any
function(s) and only generate a user-facing message.

Closes: #5954,
#8589,
#5253

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: Roger Barreto <19890735+RogerBarreto@users.noreply.github.com>
Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com>
Co-authored-by: Chris Rickman <crickman@microsoft.com>
Co-authored-by: Chris <66376200+crickman@users.noreply.github.com>
Co-authored-by: Roger Barreto <rbarreto@microsoft.com>
Co-authored-by: Dr. Artificial曾小健 <875100501@qq.com>
Co-authored-by: westey <164392973+westey-m@users.noreply.github.com>
Co-authored-by: Mark Wallace <127216156+markwallace-microsoft@users.noreply.github.com>
Co-authored-by: Tao Chen <taochen@microsoft.com>
Co-authored-by: Evan Mattson <35585003+moonbox3@users.noreply.github.com>
Co-authored-by: Maurycy Markowski <maumar@microsoft.com>
Co-authored-by: gparmigiani <jkone27@users.noreply.github.com>
Co-authored-by: Atiqur Rahman Foyshal <113086917+atiq-bs23@users.noreply.github.com>
Co-authored-by: Eduard van Valkenburg <eavanvalkenburg@users.noreply.github.com>
Co-authored-by: Andrew Desousa <33275002+andrewldesousa@users.noreply.github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

dotnet/SK-dotnet.sln

@@ -96,6 +96,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{5C246969-D
 		src\InternalUtilities\test\TestInternalUtilities.props = src\InternalUtilities\test\TestInternalUtilities.props
 	EndProjectSection
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "connectors", "connectors", "{314A2705-0F70-44B6-8988-C6DF77BDFD42}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "AI", "AI", "{C7299F56-3A55-471E-B10E-B1FBE101C625}"
+EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{958AD708-F048-4FAF-94ED-D2F2B92748B9}"
 	ProjectSection(SolutionItems) = preProject
 		src\InternalUtilities\src\InternalUtilities.props = src\InternalUtilities\src\InternalUtilities.props
@@ -326,13 +330,19 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StepwisePlannerMigration",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connectors.AzureCosmosDBNoSQL.UnitTests", "src\Connectors\Connectors.AzureCosmosDBNoSQL.UnitTests\Connectors.AzureCosmosDBNoSQL.UnitTests.csproj", "{385A8FE5-87E2-4458-AE09-35E10BD2E67F}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Connectors.Weaviate.UnitTests", "src\Connectors\Connectors.Weaviate.UnitTests\Connectors.Weaviate.UnitTests.csproj", "{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connectors.OpenAI.UnitTests", "src\Connectors\Connectors.OpenAI.UnitTests\Connectors.OpenAI.UnitTests.csproj", "{36DDC119-C030-407E-AC51-A877E9E0F660}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connectors.AzureOpenAI", "src\Connectors\Connectors.AzureOpenAI\Connectors.AzureOpenAI.csproj", "{7AAD7388-307D-41FB-B80A-EF9E3A4E31F0}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Connectors.OpenAI.UnitTests", "src\Connectors\Connectors.OpenAI.UnitTests\Connectors.OpenAI.UnitTests.csproj", "{36DDC119-C030-407E-AC51-A877E9E0F660}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connectors.AzureOpenAI.UnitTests", "src\Connectors\Connectors.AzureOpenAI.UnitTests\Connectors.AzureOpenAI.UnitTests.csproj", "{8CF06B22-50F3-4F71-A002-622DB49DF0F5}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Connectors.AzureOpenAI", "src\Connectors\Connectors.AzureOpenAI\Connectors.AzureOpenAI.csproj", "{7AAD7388-307D-41FB-B80A-EF9E3A4E31F0}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "FunctionCalling", "FunctionCalling", "{F58468D3-D635-4774-98B1-E1B5DE90A7FF}"
+	ProjectSection(SolutionItems) = preProject
+		src\InternalUtilities\connectors\AI\FunctionCalling\FunctionCallingUtilities.props = src\InternalUtilities\connectors\AI\FunctionCalling\FunctionCallingUtilities.props
+		src\InternalUtilities\connectors\AI\FunctionCalling\FunctionCallsProcessor.cs = src\InternalUtilities\connectors\AI\FunctionCalling\FunctionCallsProcessor.cs
+	EndProjectSection
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Connectors.AzureOpenAI.UnitTests", "src\Connectors\Connectors.AzureOpenAI.UnitTests\Connectors.AzureOpenAI.UnitTests.csproj", "{8CF06B22-50F3-4F71-A002-622DB49DF0F5}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Connectors.Weaviate.UnitTests", "src\Connectors\Connectors.Weaviate.UnitTests\Connectors.Weaviate.UnitTests.csproj", "{E8FC97B0-B417-4A90-993C-B8AA9223B058}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Connectors.AzureAIInference", "src\Connectors\Connectors.AzureAIInference\Connectors.AzureAIInference.csproj", "{063044B2-A901-43C5-BFDF-5E4E71C7BC33}"
 EndProject
@@ -833,12 +843,6 @@ Global
 		{385A8FE5-87E2-4458-AE09-35E10BD2E67F}.Publish|Any CPU.Build.0 = Debug|Any CPU
 		{385A8FE5-87E2-4458-AE09-35E10BD2E67F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{385A8FE5-87E2-4458-AE09-35E10BD2E67F}.Release|Any CPU.Build.0 = Release|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Publish|Any CPU.ActiveCfg = Debug|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Publish|Any CPU.Build.0 = Debug|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8}.Release|Any CPU.Build.0 = Release|Any CPU
 		{36DDC119-C030-407E-AC51-A877E9E0F660}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{36DDC119-C030-407E-AC51-A877E9E0F660}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{36DDC119-C030-407E-AC51-A877E9E0F660}.Publish|Any CPU.ActiveCfg = Debug|Any CPU
@@ -875,6 +879,12 @@ Global
 		{8972254B-B8F0-4119-953B-378E3BACA59A}.Publish|Any CPU.Build.0 = Debug|Any CPU
 		{8972254B-B8F0-4119-953B-378E3BACA59A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{8972254B-B8F0-4119-953B-378E3BACA59A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Publish|Any CPU.ActiveCfg = Debug|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Publish|Any CPU.Build.0 = Debug|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -911,6 +921,8 @@ Global
 		{6AAB0620-33A1-4A98-A63B-6560B9BA47A4} = {24503383-A8C4-4255-9998-28D70FE8E99A}
 		{50FAE231-6F24-4779-9D02-12ABBC9A49E2} = {24503383-A8C4-4255-9998-28D70FE8E99A}
 		{5C246969-D794-4EC3-8E8F-F90D4D166420} = {4D3DAE63-41C6-4E1C-A35A-E77BDFC40675}
+		{314A2705-0F70-44B6-8988-C6DF77BDFD42} = {4D3DAE63-41C6-4E1C-A35A-E77BDFC40675}
+		{C7299F56-3A55-471E-B10E-B1FBE101C625} = {314A2705-0F70-44B6-8988-C6DF77BDFD42}
 		{958AD708-F048-4FAF-94ED-D2F2B92748B9} = {4D3DAE63-41C6-4E1C-A35A-E77BDFC40675}
 		{29E7D971-1308-4171-9872-E8E4669A1134} = {958AD708-F048-4FAF-94ED-D2F2B92748B9}
 		{B00AD427-0047-4850-BEF9-BA8237EA9D8B} = {958AD708-F048-4FAF-94ED-D2F2B92748B9}
@@ -987,13 +999,14 @@ Global
 		{2918478E-BC86-4D53-9D01-9C318F80C14F} = {0247C2C9-86C3-45BA-8873-28B0948EDC0C}
 		{E06818E3-00A5-41AC-97ED-9491070CDEA1} = {5D4C0700-BBB5-418F-A7B2-F392B9A18263}
 		{385A8FE5-87E2-4458-AE09-35E10BD2E67F} = {0247C2C9-86C3-45BA-8873-28B0948EDC0C}
-		{AD9ECE32-088A-49D8-8ACB-890E79F1E7B8} = {0247C2C9-86C3-45BA-8873-28B0948EDC0C}
 		{36DDC119-C030-407E-AC51-A877E9E0F660} = {1B4CBDE0-10C2-4E7D-9CD0-FE7586C96ED1}
 		{7AAD7388-307D-41FB-B80A-EF9E3A4E31F0} = {1B4CBDE0-10C2-4E7D-9CD0-FE7586C96ED1}
 		{8CF06B22-50F3-4F71-A002-622DB49DF0F5} = {1B4CBDE0-10C2-4E7D-9CD0-FE7586C96ED1}
 		{063044B2-A901-43C5-BFDF-5E4E71C7BC33} = {1B4CBDE0-10C2-4E7D-9CD0-FE7586C96ED1}
 		{E0D45DDB-6D32-40FC-AC79-E1F342C4F513} = {1B4CBDE0-10C2-4E7D-9CD0-FE7586C96ED1}
 		{8972254B-B8F0-4119-953B-378E3BACA59A} = {5D4C0700-BBB5-418F-A7B2-F392B9A18263}
+		{F58468D3-D635-4774-98B1-E1B5DE90A7FF} = {C7299F56-3A55-471E-B10E-B1FBE101C625}
+		{E8FC97B0-B417-4A90-993C-B8AA9223B058} = {0247C2C9-86C3-45BA-8873-28B0948EDC0C}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {FBDC56A3-86AD-4323-AA0F-201E59123B83}

dotnet/samples/Concepts/Agents/ChatCompletion_FunctionTermination.cs

@@ -23,7 +23,7 @@ public async Task UseAutoFunctionInvocationFilterWithAgentInvocationAsync()
             {
                 Instructions = "Answer questions about the menu.",
                 Kernel = CreateKernelWithFilter(),
-                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions }),
+                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() }),
             };
 
         KernelPlugin plugin = KernelPluginFactory.CreateFromType<MenuPlugin>();
@@ -76,7 +76,7 @@ public async Task UseAutoFunctionInvocationFilterWithAgentChatAsync()
             {
                 Instructions = "Answer questions about the menu.",
                 Kernel = CreateKernelWithFilter(),
-                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions }),
+                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() }),
             };
 
         KernelPlugin plugin = KernelPluginFactory.CreateFromType<MenuPlugin>();

dotnet/samples/Concepts/Agents/ChatCompletion_Streaming.cs

@@ -50,7 +50,7 @@ public async Task UseStreamingChatCompletionAgentWithPluginAsync()
                 Name = "Host",
                 Instructions = MenuInstructions,
                 Kernel = this.CreateKernelWithChatCompletion(),
-                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions }),
+                Arguments = new KernelArguments(new OpenAIPromptExecutionSettings() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() }),
             };
 
         // Initialize plugin and add to the agent's Kernel (same as direct Kernel usage).

dotnet/samples/Concepts/Agents/ComplexChat_NestedShopper.cs

@@ -97,7 +97,7 @@ public async Task NestedChatWithAggregatorAgentAsync()
         Console.WriteLine($"! {Model}");
 
         OpenAIPromptExecutionSettings jsonSettings = new() { ResponseFormat = ChatResponseFormat.JsonObject };
-        OpenAIPromptExecutionSettings autoInvokeSettings = new() { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        OpenAIPromptExecutionSettings autoInvokeSettings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
 
         ChatCompletionAgent internalLeaderAgent = CreateAgent(InternalLeaderName, InternalLeaderInstructions);
         ChatCompletionAgent internalGiftIdeaAgent = CreateAgent(InternalGiftIdeaAgentName, InternalGiftIdeaAgentInstructions);

dotnet/samples/Concepts/ChatCompletion/OpenAI_ChatCompletionStreaming.cs

@@ -77,7 +77,7 @@ public async Task StreamTextContentAsync()
 
     /// <summary>
     /// This example demonstrates how the chat completion service streams raw function call content.
-    /// See <see cref="FunctionCalling.OpenAI_FunctionCalling.RunStreamingChatAPIWithManualFunctionCallingAsync"/> for a sample demonstrating how to simplify
+    /// See <see cref="FunctionCalling.FunctionCalling.RunStreamingChatCompletionApiWithManualFunctionCallingAsync"/> for a sample demonstrating how to simplify
     /// function call content building out of streamed function call updates using the <see cref="FunctionCallContentBuilder"/>.
     /// </summary>
     [Fact]
@@ -96,7 +96,7 @@ public async Task StreamFunctionCallContentAsync()
         ]);
 
         // Create execution settings with manual function calling
-        OpenAIPromptExecutionSettings settings = new() { ToolCallBehavior = ToolCallBehavior.EnableKernelFunctions };
+        OpenAIPromptExecutionSettings settings = new() { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(autoInvoke: false) };
 
         // Create chat history with initial user question
         ChatHistory chatHistory = [];

dotnet/samples/Concepts/ChatCompletion/OpenAI_FunctionCalling.cs

@@ -19,7 +19,7 @@ public async Task AutoInvokeKernelFunctionsAsync()
         const string ChatPrompt = """
             <message role="user">What is the weather like in Paris?</message>
         """;
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var chatSemanticFunction = kernel.CreateFunctionFromPrompt(
             ChatPrompt, executionSettings);
         var chatPromptResult = await kernel.InvokeAsync(chatSemanticFunction);
@@ -39,7 +39,7 @@ public async Task AutoInvokeKernelFunctionsMultipleCallsAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Paris?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result1 = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result1);
 
@@ -60,7 +60,7 @@ public async Task AutoInvokeKernelFunctionsWithComplexParameterAsync()
         const string ChatPrompt = """
             <message role="user">Book a holiday for me from 6th June 2025 to 20th June 2025?</message>
         """;
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var chatSemanticFunction = kernel.CreateFunctionFromPrompt(
             ChatPrompt, executionSettings);
         var chatPromptResult = await kernel.InvokeAsync(chatSemanticFunction);
@@ -79,7 +79,7 @@ public async Task AutoInvokeLightPluginAsync()
         const string ChatPrompt = """
             <message role="user">Turn on the light?</message>
         """;
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var chatSemanticFunction = kernel.CreateFunctionFromPrompt(
             ChatPrompt, executionSettings);
         var chatPromptResult = await kernel.InvokeAsync(chatSemanticFunction);

dotnet/samples/Concepts/ChatCompletion/OpenAI_ReasonedFunctionCalling.cs

@@ -31,7 +31,7 @@ public async Task AskAssistantToExplainFunctionCallsAfterExecutionAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Paris?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result1 = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result1);
         Console.WriteLine(result1);
@@ -57,7 +57,7 @@ public async Task UseDecoratedFunctionAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Paris?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result);
         Console.WriteLine(result);
@@ -78,7 +78,7 @@ public async Task UseDecoratedFunctionWithPromptAsync()
         string chatPrompt = """
             <message role="user">What is the weather like in Paris?</message>
             """;
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result = await kernel.InvokePromptAsync(chatPrompt, new(executionSettings));
         Console.WriteLine(result);
     }
@@ -100,7 +100,7 @@ public async Task AskAssistantToExplainFunctionCallsBeforeExecutionAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Paris?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result);
         Console.WriteLine(result);
@@ -124,7 +124,7 @@ public async Task QueryAssistantToExplainFunctionCallsBeforeExecutionAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Paris?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result);
         Console.WriteLine(result);
@@ -193,7 +193,7 @@ public async Task OnAutoFunctionInvocationAsync(AutoFunctionInvocationContext co
             {
                 new ChatMessageContent(AuthorRole.User, $"Provide an explanation why these functions: {string.Join(',', functionNames)} need to be called to answer this query: {message.Content}")
             };
-            var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.EnableKernelFunctions };
+            var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(autoInvoke: false) };
             var result = await service.GetChatMessageContentAsync(chatHistory, executionSettings, context.Kernel);
             this._output.WriteLine(result);
 

dotnet/samples/Concepts/ChatCompletion/OpenAI_RepeatedFunctionCalling.cs

@@ -28,7 +28,7 @@ public async Task ReuseFunctionResultExecutionAsync()
         {
             new ChatMessageContent(AuthorRole.User, "What is the weather like in Boston?")
         };
-        var executionSettings = new OpenAIPromptExecutionSettings { ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions };
+        var executionSettings = new OpenAIPromptExecutionSettings { FunctionChoiceBehavior = FunctionChoiceBehavior.Auto() };
         var result1 = await service.GetChatMessageContentAsync(chatHistory, executionSettings, kernel);
         chatHistory.Add(result1);
         Console.WriteLine(result1);

dotnet/samples/Concepts/Concepts.csproj

@@ -8,7 +8,7 @@
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
     <!-- Suppress: "Declare types in namespaces", "Require ConfigureAwait", "Experimental" -->
-    <NoWarn>$(NoWarn);CS8618,IDE0009,CA1051,CA1050,CA1707,CA1054,CA2007,VSTHRD111,CS1591,RCS1110,RCS1243,CA5394,SKEXP0001,SKEXP0010,SKEXP0020,SKEXP0040,SKEXP0050,SKEXP0060,SKEXP0070,SKEXP0101,SKEXP0110,OPENAI001</NoWarn>
+    <NoWarn>$(NoWarn);CS8618,IDE0009,CA1051,CA1050,CA1707,CA1054,CA2007,VSTHRD111,CS1591,RCS1110,RCS1243,CA5394,SKEXP0001,SKEXP0010,SKEXP0020,SKEXP0040,SKEXP0050,SKEXP0060,SKEXP0070,SKEXP0101,SKEXP0110,OPENAI001,CA1724</NoWarn>
     <OutputType>Library</OutputType>
     <UserSecretsId>5ee045b0-aea3-4f08-8d31-32d1a6f8fed0</UserSecretsId>
   </PropertyGroup>

dotnet/samples/Concepts/Filtering/AutoFunctionInvocationFiltering.cs

@@ -29,7 +29,7 @@ public async Task AutoFunctionInvocationFilterAsync()
 
         var executionSettings = new OpenAIPromptExecutionSettings
         {
-            ToolCallBehavior = ToolCallBehavior.RequireFunction(function.Metadata.ToOpenAIFunction(), autoInvoke: true)
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Required([function], autoInvoke: true)
         };
 
         var result = await kernel.InvokePromptAsync("Invoke provided function and return result", new(executionSettings));
@@ -76,7 +76,7 @@ public async Task GetFunctionCallsWithFilterAsync()
 
         var executionSettings = new OpenAIPromptExecutionSettings
         {
-            ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto()
         };
 
         await foreach (var chunk in kernel.InvokePromptStreamingAsync("Check current UTC time and return current weather in Boston city.", new(executionSettings)))

dotnet/samples/Concepts/Filtering/TelemetryWithFilters.cs

@@ -57,7 +57,7 @@ public async Task LoggingAsync()
         // Enable automatic function calling.
         var executionSettings = new OpenAIPromptExecutionSettings
         {
-            ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions,
+            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(),
             ModelId = "gpt-4"
         };