.Net Agents: Fix consumption of execution settings when defining agen…

…t from template. (#10519)

### Motivation and Context
<!-- Thank you for your contribution to the semantic-kernel repo!
Please help reviewers and future users, providing the following
information:
  1. Why is this change required?
  2. What problem does it solve?
  3. What scenario does it contribute to?
  4. If it fixes an open issue, please link to the issue here.
-->

When creating `ChatCompletionAgent` from a YAML resource template, the
execution-settings are not realized.

### Description
<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

- Include the execution settings when creating a `ChatCompletionAgent`
from a YAML resource template.
- Enforce never-null `KernelArguments` property on `KernelAgent`.
- Updated samples
- Added unit-tests

### Contribution Checklist
<!-- Before submitting this PR, please make sure: -->

- [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 😄

dotnet/samples/GettingStartedWithAgents/AzureAIAgent/Step01_AzureAIAgent.cs

@@ -24,7 +24,7 @@ public async Task UseTemplateForAzureAgentAsync()
         AgentsClient client = clientProvider.Client.GetAgentsClient();
         Agent definition = await client.CreateAgentAsync("gpt-4o", templateConfig.Name, templateConfig.Description, templateConfig.Template);
         // Instructions, Name and Description properties defined via the config.
-        AzureAIAgent agent = new(definition, clientProvider, new KernelPromptTemplateFactory())
+        AzureAIAgent agent = new(definition, clientProvider)
         {
             Kernel = new Kernel(),
             Arguments = new KernelArguments()

dotnet/samples/GettingStartedWithAgents/Resources/AutoInvokeTools.yaml

@@ -0,0 +1,7 @@
+name: ToolAgent
+template_format: semantic-kernel
+description: An agent that is configured to auto-invoke plugins.
+execution_settings:
+  default:
+    function_choice_behavior:
+      type: auto

dotnet/samples/GettingStartedWithAgents/Step01_Agent.cs

@@ -62,14 +62,14 @@ public async Task UseTemplateForChatCompletionAgentAsync()
 
         // Instructions, Name and Description properties defined via the config.
         ChatCompletionAgent agent =
-            new(templateConfig, new KernelPromptTemplateFactory())
+            new(templateConfig)
             {
                 Kernel = this.CreateKernelWithChatCompletion(),
-                Arguments = new KernelArguments()
-                {
-                    { "topic", "Dog" },
-                    { "length", "3" },
-                }
+                Arguments =
+                    {
+                        { "topic", "Dog" },
+                        { "length", "3" },
+                    }
             };
 
         /// Create the chat history to capture the agent interaction.

dotnet/samples/GettingStartedWithAgents/Step02_Plugins.cs

@@ -4,6 +4,7 @@
 using Microsoft.SemanticKernel.ChatCompletion;
 using Microsoft.SemanticKernel.Connectors.OpenAI;
 using Plugins;
+using Resources;
 
 namespace GettingStarted;
 
@@ -46,6 +47,30 @@ public async Task UseChatCompletionWithPluginEnumParameterAsync()
         await InvokeAgentAsync(agent, chat, "Create a beautiful red colored widget for me.");
     }
 
+    [Fact]
+    public async Task UseChatCompletionWithTemplateExecutionSettingsAsync()
+    {
+        // Read the template resource
+        string autoInvokeYaml = EmbeddedResource.Read("AutoInvokeTools.yaml");
+        PromptTemplateConfig templateConfig = KernelFunctionYaml.ToPromptTemplateConfig(autoInvokeYaml);
+
+        // Define the agent:
+        // Execution-settings with auto-invocation of plubins defined via the config.
+        ChatCompletionAgent agent =
+            new(templateConfig)
+            {
+                Kernel = this.CreateKernelWithChatCompletion()
+            };
+
+        agent.Kernel.Plugins.AddFromType<WidgetFactory>();
+
+        /// Create the chat history to capture the agent interaction.
+        ChatHistory chat = [];
+
+        // Respond to user input, invoking functions where appropriate.
+        await InvokeAgentAsync(agent, chat, "Create a beautiful red colored widget for me.");
+    }
+
     private ChatCompletionAgent CreateAgentWithPlugin(
         KernelPlugin plugin,
         string? instructions = null,

dotnet/src/Agents/Abstractions/KernelAgent.cs

@@ -17,7 +17,7 @@ public abstract class KernelAgent : Agent
     /// <remarks>
     /// Also includes <see cref="PromptExecutionSettings"/>.
     /// </remarks>
-    public KernelArguments? Arguments { get; init; }
+    public KernelArguments Arguments { get; init; } = [];
 
     /// <summary>
     /// Gets the instructions for the agent (optional).
@@ -73,14 +73,8 @@ public abstract class KernelAgent : Agent
     /// It allows for incremental addition or replacement of specific parameters while also preserving the ability
     /// to override the execution settings.
     /// </remarks>
-    protected KernelArguments? MergeArguments(KernelArguments? arguments)
+    protected KernelArguments MergeArguments(KernelArguments? arguments)
     {
-        // Avoid merge when default arguments are not set.
-        if (this.Arguments == null)
-        {
-            return arguments;
-        }
-
         // Avoid merge when override arguments are not set.
         if (arguments == null)
         {

dotnet/src/Agents/Core/ChatCompletionAgent.cs

@@ -43,6 +43,7 @@ public ChatCompletionAgent(
         this.Name = templateConfig.Name;
         this.Description = templateConfig.Description;
         this.Instructions = templateConfig.Template;
+        this.Arguments = new(templateConfig.ExecutionSettings.Values);
         this.Template = templateFactory?.Create(templateConfig);
     }
 

dotnet/src/Agents/OpenAI/OpenAIAssistantAgent.cs

@@ -138,7 +138,7 @@ public static async Task<OpenAIAssistantAgent> CreateAsync(
             new OpenAIAssistantAgent(model, clientProvider, client)
             {
                 Kernel = kernel,
-                Arguments = defaultArguments
+                Arguments = defaultArguments ?? [],
             };
     }
 
@@ -176,7 +176,7 @@ public static async Task<OpenAIAssistantAgent> CreateAsync(
             new OpenAIAssistantAgent(model, clientProvider, client)
             {
                 Kernel = kernel,
-                Arguments = defaultArguments
+                Arguments = defaultArguments ?? [],
             };
     }
 
@@ -240,7 +240,7 @@ public static async Task<OpenAIAssistantAgent> RetrieveAsync(
             new OpenAIAssistantAgent(model, clientProvider, client)
             {
                 Kernel = kernel,
-                Arguments = defaultArguments,
+                Arguments = defaultArguments ?? [],
                 Template = template,
             };
     }

dotnet/src/Agents/UnitTests/Core/ChatCompletionAgentTests.cs

@@ -37,7 +37,52 @@ public void VerifyChatCompletionAgentDefinition()
         Assert.Equal("test instructions", agent.Instructions);
         Assert.Equal("test description", agent.Description);
         Assert.Equal("test name", agent.Name);
-        Assert.Null(agent.Arguments);
+        Assert.NotNull(agent.Arguments);
+    }
+
+    /// <summary>
+    /// Verify the invocation and response of <see cref="ChatCompletionAgent"/>.
+    /// </summary>
+    [Fact]
+    public void VerifyChatCompletionAgentTemplate()
+    {
+        PromptTemplateConfig config =
+            new()
+            {
+                Name = "TestName",
+                Description = "TestDescription",
+                Template = "TestInstructions",
+                ExecutionSettings =
+                {
+                    {
+                        PromptExecutionSettings.DefaultServiceId,
+                        new PromptExecutionSettings()
+                        {
+                            FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(),
+                            ModelId = "gpt-new",
+                        }
+                    },
+                    {
+                        "manual",
+                        new PromptExecutionSettings()
+                        {
+                            ServiceId = "manual",
+                            FunctionChoiceBehavior = FunctionChoiceBehavior.Required(),
+                            ModelId = "gpt-old",
+                        }
+                    },
+                }
+            };
+
+        // Arrange
+        ChatCompletionAgent agent = new(config);
+
+        // Assert
+        Assert.NotNull(agent.Id);
+        Assert.Equal(config.Template, agent.Instructions);
+        Assert.Equal(config.Description, agent.Description);
+        Assert.Equal(config.Name, agent.Name);
+        Assert.Equal(config.ExecutionSettings, agent.Arguments.ExecutionSettings);
     }
 
     /// <summary>

dotnet/src/Agents/UnitTests/KernelAgentTests.cs

@@ -18,19 +18,18 @@ public class KernelAgentTests
     public void VerifyNullArgumentMerge()
     {
         // Arrange
-        MockAgent agentWithNullArguments = new();
+        MockAgent agentWithNoArguments = new();
         // Act
-        KernelArguments? arguments = agentWithNullArguments.MergeArguments(null);
+        KernelArguments arguments = agentWithNoArguments.MergeArguments(null);
         // Assert
-        Assert.Null(arguments);
+        Assert.Empty(arguments);
 
         // Arrange
-        KernelArguments overrideArguments = [];
+        KernelArguments overrideArguments = new() { { "test", 1 } };
         // Act
-        arguments = agentWithNullArguments.MergeArguments(overrideArguments);
+        arguments = agentWithNoArguments.MergeArguments(overrideArguments);
         // Assert
-        Assert.NotNull(arguments);
-        Assert.StrictEqual(overrideArguments, arguments);
+        Assert.StrictEqual(1, arguments.Count);
 
         // Arrange
         MockAgent agentWithEmptyArguments = new() { Arguments = new() };

dotnet/src/Agents/UnitTests/MockAgent.cs

@@ -41,7 +41,7 @@ public override IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsy
     }
 
     // Expose protected method for testing
-    public new KernelArguments? MergeArguments(KernelArguments? arguments)
+    public new KernelArguments MergeArguments(KernelArguments? arguments)
     {
         return base.MergeArguments(arguments);
     }