fix: project copilot tool results into workflows

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

sidecar/src/Aryx.AgentHost/Services/AryxCopilotAgent.cs

@@ -1,3 +1,4 @@
+using System.Collections.Concurrent;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Text.Json;
@@ -104,6 +105,7 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
         try
         {
             Channel<AgentResponseUpdate> channel = Channel.CreateUnbounded<AgentResponseUpdate>();
+            ConcurrentDictionary<string, string> toolNamesByCallId = new(StringComparer.Ordinal);
 
             using IDisposable subscription = copilotSession.On(evt =>
             {
@@ -114,9 +116,19 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
                         break;
 
                     case AssistantMessageEvent assistantMessage:
+                        TrackToolRequestNames(toolNamesByCallId, assistantMessage.Data?.ToolRequests);
                         channel.Writer.TryWrite(ConvertToAgentResponseUpdate(assistantMessage));
                         break;
 
+                    case ToolExecutionCompleteEvent toolExecutionComplete:
+                        AgentResponseUpdate? toolResultUpdate = ConvertToAgentResponseUpdate(toolExecutionComplete, toolNamesByCallId);
+                        if (toolResultUpdate is not null)
+                        {
+                            channel.Writer.TryWrite(toolResultUpdate);
+                        }
+
+                        break;
+
                     case AssistantUsageEvent usageEvent:
                         channel.Writer.TryWrite(ConvertToAgentResponseUpdate(usageEvent));
                         break;
@@ -232,16 +244,6 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
                 continue;
             }
 
-            // Only project handoff tool calls as FunctionCallContent for the Agent Framework.
-            // Other tool calls (ask_user, MCP tools, etc.) are resolved by the Copilot SDK
-            // internally and must not be surfaced, because AIAgentHostExecutor tracks every
-            // FunctionCallContent as an outstanding request.  An unmatched request prevents
-            // the executor from emitting a TurnToken, which stalls group-chat advancement.
-            if (!IsHandoffToolName(toolRequest.Name))
-            {
-                continue;
-            }
-
             contents.Add(new FunctionCallContent(
                 toolRequest.ToolCallId,
                 toolRequest.Name,
@@ -251,6 +253,26 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
         return contents;
     }
 
+    internal static FunctionResultContent? TryCreateToolResultContent(
+        ToolExecutionCompleteEvent toolExecutionComplete,
+        string? toolName = null)
+    {
+        // Regular Copilot tools need their result projected back into AF so the function call
+        // remains part of workflow-visible history. Handoff tools are finalized separately by
+        // HandoffAgentExecutor, which already injects its own "Transferred." result.
+        string? toolCallId = toolExecutionComplete.Data?.ToolCallId?.Trim();
+        if (string.IsNullOrWhiteSpace(toolCallId) || IsHandoffToolName(toolName))
+        {
+            return null;
+        }
+
+        string result = ResolveToolResultText(toolExecutionComplete.Data);
+        return new FunctionResultContent(toolCallId, result)
+        {
+            RawRepresentation = toolExecutionComplete,
+        };
+    }
+
     private static bool IsHandoffToolName(string? name)
     {
         return !string.IsNullOrWhiteSpace(name)
@@ -441,6 +463,36 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
         };
     }
 
+    private AgentResponseUpdate? ConvertToAgentResponseUpdate(
+        ToolExecutionCompleteEvent toolExecutionComplete,
+        ConcurrentDictionary<string, string> toolNamesByCallId)
+    {
+        string? toolCallId = toolExecutionComplete.Data?.ToolCallId?.Trim();
+        if (string.IsNullOrWhiteSpace(toolCallId))
+        {
+            return null;
+        }
+
+        string? toolName = null;
+        if (toolNamesByCallId.TryRemove(toolCallId, out string? trackedToolName))
+        {
+            toolName = trackedToolName;
+        }
+
+        FunctionResultContent? toolResult = TryCreateToolResultContent(toolExecutionComplete, toolName);
+        if (toolResult is null)
+        {
+            return null;
+        }
+
+        return new AgentResponseUpdate(ChatRole.Tool, [toolResult])
+        {
+            AgentId = Id,
+            MessageId = toolCallId,
+            CreatedAt = toolExecutionComplete.Timestamp,
+        };
+    }
+
     private AgentResponseUpdate ConvertToAgentResponseUpdate(SessionEvent sessionEvent)
     {
         AIContent content = new()
@@ -455,6 +507,45 @@ internal sealed class AryxCopilotAgent : AIAgent, IAsyncDisposable
         };
     }
 
+    private static void TrackToolRequestNames(
+        ConcurrentDictionary<string, string> toolNamesByCallId,
+        AssistantMessageDataToolRequestsItem[]? toolRequests)
+    {
+        if (toolRequests is not { Length: > 0 })
+        {
+            return;
+        }
+
+        foreach (AssistantMessageDataToolRequestsItem toolRequest in toolRequests)
+        {
+            string? toolCallId = toolRequest.ToolCallId?.Trim();
+            string? toolName = toolRequest.Name?.Trim();
+            if (string.IsNullOrWhiteSpace(toolCallId) || string.IsNullOrWhiteSpace(toolName))
+            {
+                continue;
+            }
+
+            toolNamesByCallId[toolCallId] = toolName;
+        }
+    }
+
+    private static string ResolveToolResultText(ToolExecutionCompleteData? toolExecutionCompleteData)
+    {
+        if (toolExecutionCompleteData is null)
+        {
+            return string.Empty;
+        }
+
+        if (toolExecutionCompleteData.Success)
+        {
+            return toolExecutionCompleteData.Result?.Content
+                ?? toolExecutionCompleteData.Result?.DetailedContent
+                ?? string.Empty;
+        }
+
+        return toolExecutionCompleteData.Error?.Message ?? string.Empty;
+    }
+
     private static Dictionary<string, object?>? ParseToolArguments(object? arguments)
     {
         if (arguments is null)

sidecar/src/Aryx.AgentHost/Services/CopilotTurnExecutionState.cs

@@ -89,7 +89,16 @@ internal sealed class CopilotTurnExecutionState
             case ToolExecutionStartEvent toolExecutionStart
                 when !string.IsNullOrWhiteSpace(toolExecutionStart.Data?.ToolCallId)
                     && !string.IsNullOrWhiteSpace(toolExecutionStart.Data?.ToolName):
-                ToolNamesByCallId[toolExecutionStart.Data.ToolCallId.Trim()] = toolExecutionStart.Data.ToolName.Trim();
+                string toolCallId = toolExecutionStart.Data.ToolCallId.Trim();
+                string toolName = toolExecutionStart.Data.ToolName.Trim();
+                ToolNamesByCallId[toolCallId] = toolName;
+                ActiveAgent = agent;
+                AgentActivityEventDto? toolActivity = CreateToolCallingActivity(agent, toolName, toolCallId);
+                if (toolActivity is not null)
+                {
+                    _pendingEvents.Enqueue(toolActivity);
+                }
+
                 QueueMessageReclassifiedIfNeeded(_lastObservedMessageId);
                 break;
             case AssistantIntentEvent intentEvent:
@@ -278,6 +287,29 @@ internal sealed class CopilotTurnExecutionState
         };
     }
 
+    private AgentActivityEventDto? CreateToolCallingActivity(
+        AgentIdentity agent,
+        string toolName,
+        string toolCallId)
+    {
+        if (toolName.StartsWith("handoff_to_", StringComparison.Ordinal))
+        {
+            return null;
+        }
+
+        return new AgentActivityEventDto
+        {
+            Type = "agent-activity",
+            RequestId = _command.RequestId,
+            SessionId = _command.SessionId,
+            ActivityType = "tool-calling",
+            AgentId = agent.AgentId,
+            AgentName = agent.AgentName,
+            ToolName = toolName,
+            ToolCallId = toolCallId,
+        };
+    }
+
     private MessageReclassifiedEventDto CreateMessageReclassifiedEvent(string messageId)
     {
         return new MessageReclassifiedEventDto

sidecar/src/Aryx.AgentHost/Services/WorkflowRequestInfoInterpreter.cs

@@ -57,12 +57,17 @@ internal static class WorkflowRequestInfoInterpreter
         };
     }
 
-    private static AgentActivityEventDto CreateToolCallingActivity(
+    private static AgentActivityEventDto? CreateToolCallingActivity(
         RunTurnCommandDto command,
         AgentIdentity activeAgent,
         ToolRequestInterpretation tool,
         ConcurrentDictionary<string, string> toolNamesByCallId)
     {
+        if (tool.ToolCallId is not null && toolNamesByCallId.ContainsKey(tool.ToolCallId))
+        {
+            return null;
+        }
+
         TrackToolCallId(toolNamesByCallId, tool.ToolCallId, tool.ToolName);
 
         return new AgentActivityEventDto

sidecar/tests/Aryx.AgentHost.Tests/CopilotAgentBundleTests.cs

@@ -185,7 +185,7 @@ public sealed class CopilotAgentBundleTests
     }
 
     [Fact]
-    public void ConvertToolRequestsToFunctionCalls_SkipsNonHandoffToolCalls()
+    public void ConvertToolRequestsToFunctionCalls_MapsNonHandoffToolCalls()
     {
         AssistantMessageDataToolRequestsItem[] toolRequests =
         {
@@ -197,9 +197,99 @@ public sealed class CopilotAgentBundleTests
 
         IReadOnlyList<FunctionCallContent> result = AryxCopilotAgent.ConvertToolRequestsToFunctionCalls(toolRequests);
 
-        FunctionCallContent single = Assert.Single(result);
+        Assert.Collection(
-        Assert.Equal("call-003", single.CallId);
+            result,
-        Assert.Equal("handoff_to_reviewer", single.Name);
+            functionCall =>
+            {
+                Assert.Equal("call-001", functionCall.CallId);
+                Assert.Equal("ask_user", functionCall.Name);
+            },
+            functionCall =>
+            {
+                Assert.Equal("call-002", functionCall.CallId);
+                Assert.Equal("web_fetch", functionCall.Name);
+            },
+            functionCall =>
+            {
+                Assert.Equal("call-003", functionCall.CallId);
+                Assert.Equal("handoff_to_reviewer", functionCall.Name);
+            },
+            functionCall =>
+            {
+                Assert.Equal("call-004", functionCall.CallId);
+                Assert.Equal("grep", functionCall.Name);
+            });
+    }
+
+    [Fact]
+    public void TryCreateToolResultContent_UsesSdkResultContentForNonHandoffTools()
+    {
+        ToolExecutionCompleteEvent toolExecutionComplete = new()
+        {
+            Data = new ToolExecutionCompleteData
+            {
+                ToolCallId = "call-123",
+                Success = true,
+                Result = new ToolExecutionCompleteDataResult
+                {
+                    Content = "Search complete.",
+                    DetailedContent = "Search complete with extra context.",
+                },
+            },
+        };
+
+        FunctionResultContent? toolResult = AryxCopilotAgent.TryCreateToolResultContent(toolExecutionComplete, "rg");
+
+        Assert.NotNull(toolResult);
+        Assert.Equal("call-123", toolResult.CallId);
+        Assert.Equal("Search complete.", Assert.IsType<string>(toolResult.Result));
+        Assert.Same(toolExecutionComplete, toolResult.RawRepresentation);
+    }
+
+    [Fact]
+    public void TryCreateToolResultContent_UsesSdkErrorMessageForFailedTools()
+    {
+        ToolExecutionCompleteEvent toolExecutionComplete = new()
+        {
+            Data = new ToolExecutionCompleteData
+            {
+                ToolCallId = "call-456",
+                Success = false,
+                Error = new ToolExecutionCompleteDataError
+                {
+                    Message = "Permission denied.",
+                },
+            },
+        };
+
+        FunctionResultContent? toolResult = AryxCopilotAgent.TryCreateToolResultContent(toolExecutionComplete, "view");
+
+        Assert.NotNull(toolResult);
+        Assert.Equal("call-456", toolResult.CallId);
+        Assert.Equal("Permission denied.", Assert.IsType<string>(toolResult.Result));
+    }
+
+    [Fact]
+    public void TryCreateToolResultContent_SkipsHandoffTools()
+    {
+        ToolExecutionCompleteEvent toolExecutionComplete = new()
+        {
+            Data = new ToolExecutionCompleteData
+            {
+                ToolCallId = "call-789",
+                Success = true,
+                Result = new ToolExecutionCompleteDataResult
+                {
+                    Content = "Transferred.",
+                },
+            },
+        };
+
+        FunctionResultContent? toolResult = AryxCopilotAgent.TryCreateToolResultContent(
+            toolExecutionComplete,
+            "handoff_to_reviewer");
+
+        Assert.Null(toolResult);
     }
 
     [Fact]

sidecar/tests/Aryx.AgentHost.Tests/CopilotTurnExecutionStateTests.cs

@@ -60,7 +60,7 @@ public sealed class CopilotTurnExecutionStateTests
     }
 
     [Fact]
-    public void ObserveSessionEvent_ToolExecutionStart_TracksToolNameByCallId()
+    public void ObserveSessionEvent_ToolExecutionStart_TracksToolNameByCallIdAndQueuesToolActivity()
     {
         RunTurnCommandDto command = CreateCommand();
         CopilotTurnExecutionState state = new(command);
@@ -68,22 +68,32 @@ public sealed class CopilotTurnExecutionStateTests
         state.ObserveSessionEvent(
             command.Pattern.Agents[0],
             SessionEvent.FromJson(
-                """
+                """{"type":"tool.execution_start","data":{"toolCallId":"tool-call-1","toolName":"view"},"id":"33333333-3333-3333-3333-333333333333","timestamp":"2026-03-27T00:00:00Z"}"""));
-                {
-                  "type": "tool.execution_start",
-                  "data": {
-                    "toolCallId": "tool-call-1",
-                    "toolName": "view"
-                  },
-                  "id": "33333333-3333-3333-3333-333333333333",
-                  "timestamp": "2026-03-27T00:00:00Z"
-                }
-                """));
 
+        AgentActivityEventDto toolActivity = Assert.Single(state.DrainPendingEvents().OfType<AgentActivityEventDto>());
+        Assert.Equal("tool-calling", toolActivity.ActivityType);
+        Assert.Equal("view", toolActivity.ToolName);
+        Assert.Equal("tool-call-1", toolActivity.ToolCallId);
         Assert.True(state.ToolNamesByCallId.TryGetValue("tool-call-1", out string? toolName));
         Assert.Equal("view", toolName);
     }
 
+    [Fact]
+    public void ObserveSessionEvent_ToolExecutionStart_DoesNotQueueToolActivityForHandoffTools()
+    {
+        RunTurnCommandDto command = CreateCommand();
+        CopilotTurnExecutionState state = new(command);
+
+        state.ObserveSessionEvent(
+            command.Pattern.Agents[0],
+            SessionEvent.FromJson(
+                """{"type":"tool.execution_start","data":{"toolCallId":"tool-call-1","toolName":"handoff_to_specialist"},"id":"1ce9d1dc-68f1-4df5-9728-f97017233279","timestamp":"2026-03-27T00:00:00Z"}"""));
+
+        Assert.Empty(state.DrainPendingEvents().OfType<AgentActivityEventDto>());
+        Assert.True(state.ToolNamesByCallId.TryGetValue("tool-call-1", out string? toolName));
+        Assert.Equal("handoff_to_specialist", toolName);
+    }
+
     [Fact]
     public void ObserveSessionEvent_AssistantMessageWithToolRequests_QueuesMessageReclassifiedEvent()
     {
@@ -178,6 +188,10 @@ public sealed class CopilotTurnExecutionStateTests
 
         IReadOnlyList<SidecarEventDto> pending = state.DrainPendingEvents();
 
+        AgentActivityEventDto[] toolActivities = [.. pending.OfType<AgentActivityEventDto>().Where(activity => activity.ActivityType == "tool-calling")];
+        Assert.Equal(2, toolActivities.Length);
+        Assert.Contains(toolActivities, activity => activity.ToolCallId == "tool-call-1" && activity.ToolName == "rg");
+        Assert.Contains(toolActivities, activity => activity.ToolCallId == "tool-call-2" && activity.ToolName == "view");
         MessageReclassifiedEventDto reclassified = Assert.Single(pending.OfType<MessageReclassifiedEventDto>());
         Assert.Equal("msg-3", reclassified.MessageId);
         Assert.True(state.ToolNamesByCallId.TryGetValue("tool-call-1", out string? firstToolName));

sidecar/tests/Aryx.AgentHost.Tests/WorkflowRequestInfoInterpreterTests.cs

@@ -86,6 +86,26 @@ public sealed class WorkflowRequestInfoInterpreterTests
         Assert.Empty(toolNamesByCallId);
     }
 
+    [Fact]
+    public void TryCreateActivityFromRequest_SkipsDuplicateTrackedToolCallIds()
+    {
+        ConcurrentDictionary<string, string> toolNamesByCallId = new(StringComparer.Ordinal)
+        {
+            ["call-1"] = "view",
+        };
+        RequestInfoEvent requestInfo = CreateRequestInfoEvent(
+            new FunctionCallContent("call-1", "view", new Dictionary<string, object?>()));
+
+        AgentActivityEventDto? activity = WorkflowRequestInfoInterpreter.TryCreateActivityFromRequest(
+            CreateSingleAgentCommand(),
+            requestInfo,
+            new AgentIdentity("agent-1", "Primary"),
+            toolNamesByCallId);
+
+        Assert.Null(activity);
+        Assert.Equal("view", toolNamesByCallId["call-1"]);
+    }
+
     [Fact]
     public void TryCreateActivityFromRequest_ReturnsHandoffActivityForKnownTargets()
     {