Generated tool input schema for reflected C# parameter objects does not satisfy OpenAI strict function schema requirements in VS Copilot. #1447
Description
MCP .NET SDK version: 1.10 (Also on 0.40 version of SDK)
VS: 18.2.2
[McpServerTool] method with object-typed input
error first on additionalProperties, then on missing required entries.
I have a input model which has nested object properties
Ex ->
Class inputParameter
{
public INestedObject nestedProperty;
}
Only while using OpenAI models.
I see error stated below
Invalid schema for function 'functioname': In context=('properties', 'inputParameter'), 'additionalProperties' is required to be supplied and to be false. at OpenAI.ClientPipelineExtensions.ProcessMessageAsync(ClientPipeline pipeline, PipelineMessage message, RequestOptions options) at OpenAI.Responses.OpenAIResponseClient.CreateResponseAsync(BinaryContent content, RequestOptions options) at OpenAI.Responses.OpenAIResponseClient.<>c__DisplayClass13_0.<b__0>d.MoveNext() --- End of stack trace from previous location --- at OpenAI.AsyncSseUpdateCollection1.GetRawPagesAsync()+MoveNext() at OpenAI.AsyncSseUpdateCollection1.GetRawPagesAsync()+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult() at System.ClientModel.AsyncCollectionResult1.GetAsyncEnumerator(CancellationToken cancellationToken)+MoveNext() at System.ClientModel.AsyncCollectionResult1.GetAsyncEnumerator(CancellationToken cancellationToken)+MoveNext() at System.ClientModel.AsyncCollectionResult1.GetAsyncEnumerator(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult() at Microsoft.VisualStudio.Conversations.CopilotClient.CopilotAPIClient.ChatCoreWithResponsesAPIAsync(HttpClient httpClient, ChatRequestOptions requestOptions, CancellationToken cancellationToken) at Microsoft.VisualStudio.Conversations.CopilotClient.CopilotAPIClient.ChatCoreWithResponsesAPIAsync(HttpClient httpClient, ChatRequestOptions requestOptions, CancellationToken cancellationToken) at Microsoft.VisualStudio.Conversations.CopilotClient.CopilotAPIClient.ChatCoreAsync(HttpClient httpClient, CopilotAPIRequest request, Action1 onToken, Action1 onUpdate, CopilotInteractionId interactionId, Boolean validateRootRequestId, String sessionToken, CancellationToken cancellationToken) at Conversations.Kernel.LLMClient.GetGitHubApiResponseAsync(CopilotAPIRequest request, CopilotInteractionId interactionId, Action1 onToken, Action1 onUpdate, String sessionToken, CancellationToken cancellationToken) at Conversations.Kernel.LLMClient.GetApiResponseAsync(CopilotAPIRequest request, CopilotInteractionId interactionId, Action1 onToken, Action1 onUpdate, String sessionToken, CancellationToken cancellationToken) at Conversations.Kernel.LLMClient.RequestAsync(CopilotAPIRequest request, CopilotInteractionId interactionId, ICopilotStreamingContentSink streamTarget, String sessionToken, CancellationToken cancellationToken); at StreamJsonRpc.JsonRpc.d__1711.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.VisualStudio.Copilot.ResponderBroker.d__9.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at Microsoft.VisualStudio.Copilot.ResponderBroker.d__9.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.Copilot.ResponderBroker.d__3.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Threading.Tasks.Sources.ManualResetValueTaskSourceCore1.GetResult(Int16 token) at Microsoft.VisualStudio.Copilot.Core.Agents.CopilotAgentModeResponder.d__14.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Threading.Tasks.Sources.ManualResetValueTaskSourceCore1.GetResult(Int16 token) at Microsoft.VisualStudio.Copilot.CopilotDefaultOrchestrator.d__24.MoveNext() RPC server exception: System.Exception: Error occurred while invoking intent 'Generic'.