Error in sequential workflow with MCP tool calls.

[drkclw]

I am building a sequential workflow with 2 agents, the first one calls an MCP server and runs without issues. However, when the second agent tries to execute I am seeing the following error:

ExecutorInvokedEvent(Executor = 2d5f9d2e5d3e4a29b8417dfad5b373e0, Data: Microsoft.Agents.AI.Workflows.TurnToken = Microsoft.Agents.AI.Workflows.TurnToken)
ExecutorFailedEvent(Executor = 2d5f9d2e5d3e4a29b8417dfad5b373e0, Data: System.ClientModel.ClientResultException = System.ClientModel.ClientResultException: HTTP 400 (invalid_request_error: )
Parameter: messages.[2].role

Invalid parameter: messages with role 'tool' must be a response to a preceeding message with 'tool_calls'.
at OpenAI.ClientPipelineExtensions.ProcessMessageAsync(ClientPipeline pipeline, PipelineMessage message, RequestOptions options)
at OpenAI.Chat.ChatClient.CompleteChatAsync(BinaryContent content, RequestOptions options)
at OpenAI.Chat.ChatClient.<>c__DisplayClass19_0.<b__0>d.MoveNext()
--- End of stack trace from previous location ---
at OpenAI.AsyncSseUpdateCollection`1.GetRawPagesAsync()+MoveNext()

Below is the code I am using:

var workflow = new WorkflowBuilder(agent).AddEdge(agent, jokeAgent).Build();
var messages = new List<ChatMessage> { new(ChatRole.User, $"{{ \"id\": \"123\" }}") };

StreamingRun run = await InProcessExecution.StreamAsync(workflow, messages);
await run.TrySendMessageAsync(new TurnToken(emitEvents: true));