From a442ee115dc9f27bb39cb0cfc7ce5cd8be37e931 Mon Sep 17 00:00:00 2001
From: Roger Barreto <19890735+rogerbarreto@users.noreply.github.com>
Date: Mon, 2 Mar 2026 22:12:55 +0000
Subject: [PATCH] .NET: AzureAI Package - Skip tool validation when
 UseProvidedChatClientAsIs is true (#4389)

* Skip tool validation when UseProvidedChatClientAsIs is true (#3855)

When GetAIAgentAsync is called with ChatClientAgentOptions.UseProvidedChatClientAsIs = true,
skip requireInvocableTools validation so users can handle function calls manually
via custom ChatClient middleware without needing to provide matching AIFunction tools.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Simplify requireInvocableTools expression per review feedback

UseProvidedChatClientAsIs is a non-nullable bool, so use ! operator
instead of != true for clarity.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Decouple tool matching from validation and add tool preservation test (#3855)

Always match provided AIFunctions to server-side function definitions
regardless of requireInvocableTools flag. Only throw when validation
is required and no match is found. This ensures UseProvidedChatClientAsIs
still preserves user-provided AIFunction tools instead of falling back
to the broken ResponseToolAITool wrapper.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../AzureAIProjectChatClientExtensions.cs     | 20 +++---
 ...AzureAIProjectChatClientExtensionsTests.cs | 64 +++++++++++++++++++
 2 files changed, 75 insertions(+), 9 deletions(-)

diff --git a/dotnet/src/Microsoft.Agents.AI.AzureAI/AzureAIProjectChatClientExtensions.cs b/dotnet/src/Microsoft.Agents.AI.AzureAI/AzureAIProjectChatClientExtensions.cs
index 027eea1bca..a190f4b154 100644
--- a/dotnet/src/Microsoft.Agents.AI.AzureAI/AzureAIProjectChatClientExtensions.cs
+++ b/dotnet/src/Microsoft.Agents.AI.AzureAI/AzureAIProjectChatClientExtensions.cs
@@ -191,7 +191,7 @@ public static partial class AzureAIProjectChatClientExtensions
         AgentRecord agentRecord = await GetAgentRecordByNameAsync(aiProjectClient, options.Name, cancellationToken).ConfigureAwait(false);
         var agentVersion = agentRecord.Versions.Latest;
 
-        var agentOptions = CreateChatClientAgentOptions(agentVersion, options, requireInvocableTools: true);
+        var agentOptions = CreateChatClientAgentOptions(agentVersion, options, requireInvocableTools: !options.UseProvidedChatClientAsIs);
 
         return AsChatClientAgent(
             aiProjectClient,
@@ -522,21 +522,23 @@ public static partial class AzureAIProjectChatClientExtensions
             // Check function tools
             foreach (ResponseTool responseTool in definitionTools)
             {
-                if (requireInvocableTools && responseTool is FunctionTool functionTool)
+                if (responseTool is FunctionTool functionTool)
                 {
                     // Check if a tool with the same type and name exists in the provided tools.
-                    // When invocable tools are required, match only AIFunction.
+                    // Always prefer matching AIFunction when available, regardless of requireInvocableTools.
                     var matchingTool = chatOptions?.Tools?.FirstOrDefault(t => t is AIFunction tf && functionTool.FunctionName == tf.Name);
 
-                    if (matchingTool is null)
-                    {
-                        (missingTools ??= []).Add($"Function tool: {functionTool.FunctionName}");
-                    }
-                    else
+                    if (matchingTool is not null)
                     {
                         (agentTools ??= []).Add(matchingTool!);
+                        continue;
+                    }
+
+                    if (requireInvocableTools)
+                    {
+                        (missingTools ??= []).Add($"Function tool: {functionTool.FunctionName}");
+                        continue;
                     }
-                    continue;
                 }
 
                 (agentTools ??= []).Add(responseTool.AsAITool());
diff --git a/dotnet/tests/Microsoft.Agents.AI.AzureAI.UnitTests/AzureAIProjectChatClientExtensionsTests.cs b/dotnet/tests/Microsoft.Agents.AI.AzureAI.UnitTests/AzureAIProjectChatClientExtensionsTests.cs
index 2f2e276ae9..a7b9c54aac 100644
--- a/dotnet/tests/Microsoft.Agents.AI.AzureAI.UnitTests/AzureAIProjectChatClientExtensionsTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.AzureAI.UnitTests/AzureAIProjectChatClientExtensionsTests.cs
@@ -2375,6 +2375,70 @@ public sealed class AzureAIProjectChatClientExtensionsTests
         Assert.NotNull(agent);
     }
 
+    /// <summary>
+    /// Verify that GetAIAgentAsync with UseProvidedChatClientAsIs=true skips tool validation
+    /// and does not throw even when server-side function tools exist without matching invocable tools.
+    /// </summary>
+    [Fact]
+    public async Task GetAIAgentAsync_WithUseProvidedChatClientAsIs_SkipsToolValidationAsync()
+    {
+        // Arrange
+        PromptAgentDefinition definition = new("test-model") { Instructions = "Test" };
+        definition.Tools.Add(ResponseTool.CreateFunctionTool("required_function", BinaryData.FromString("{}"), strictModeEnabled: false));
+
+        AIProjectClient client = this.CreateTestAgentClient(agentDefinitionResponse: definition);
+        var options = new ChatClientAgentOptions
+        {
+            Name = "test-agent",
+            ChatOptions = new ChatOptions { Instructions = "Test" },
+            UseProvidedChatClientAsIs = true
+        };
+
+        // Act - should not throw even without tools when UseProvidedChatClientAsIs is true
+        ChatClientAgent agent = await client.GetAIAgentAsync(options);
+
+        // Assert
+        Assert.NotNull(agent);
+    }
+
+    /// <summary>
+    /// Verify that GetAIAgentAsync with UseProvidedChatClientAsIs=true still matches provided AIFunction tools
+    /// to server-side function definitions, instead of falling back to the ResponseToolAITool wrapper.
+    /// </summary>
+    [Fact]
+    public async Task GetAIAgentAsync_WithUseProvidedChatClientAsIs_PreservesProvidedToolsAsync()
+    {
+        // Arrange
+        PromptAgentDefinition definition = new("test-model") { Instructions = "Test" };
+        definition.Tools.Add(ResponseTool.CreateFunctionTool("my_function", BinaryData.FromString("{}"), strictModeEnabled: false));
+
+        AIProjectClient client = this.CreateTestAgentClient(agentDefinitionResponse: definition);
+
+        var providedTool = AIFunctionFactory.Create(() => "test", "my_function", "A test function");
+        var options = new ChatClientAgentOptions
+        {
+            Name = "test-agent",
+            UseProvidedChatClientAsIs = true,
+            ChatOptions = new ChatOptions
+            {
+                Instructions = "Test",
+                Tools = [providedTool]
+            },
+        };
+
+        // Act - UseProvidedChatClientAsIs is true, but provided AIFunctions should still be matched and preserved
+        ChatClientAgent agent = await client.GetAIAgentAsync(options);
+
+        // Assert
+        Assert.NotNull(agent);
+
+        // Verify the provided AIFunction was matched and preserved in ChatOptions.Tools (not replaced by AsAITool wrapper)
+        var chatOptions = agent.GetService<ChatOptions>();
+        Assert.NotNull(chatOptions);
+        Assert.NotNull(chatOptions!.Tools);
+        Assert.Contains(chatOptions.Tools, t => t is AIFunction af && af.Name == "my_function");
+    }
+
     #endregion
 
     #region Empty Version and ID Handling Tests