Fix Eino final output fallback capture

internal/multiagent/eino_exit_fallback_test.go

@@ -55,6 +55,70 @@ func TestEinoExtractFallbackAssistantFromMsgs_prefersToolOverEarlierAssistant(t
 	}
 }
 
+func TestEinoExtractFallbackAssistantFromMsgs_plainAssistant(t *testing.T) {
+	msgs := []*schema.Message{
+		schema.UserMessage("hi"),
+		schema.AssistantMessage("plain answer", nil),
+	}
+	if got := einoExtractFallbackAssistantFromMsgs(msgs); got != "plain answer" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestEinoExtractFallbackAssistantFromMsgs_finalAssistantAfterToolResult(t *testing.T) {
+	msgs := []*schema.Message{
+		schema.UserMessage("hi"),
+		schema.AssistantMessage("", []schema.ToolCall{{
+			ID:   "call-1",
+			Type: "function",
+			Function: schema.FunctionCall{
+				Name:      "execute",
+				Arguments: `{"command":"pwd"}`,
+			},
+		}}),
+		schema.ToolMessage("/tmp", "call-1", schema.WithToolName("execute")),
+		schema.AssistantMessage("final after tool", nil),
+	}
+	if got := einoExtractFallbackAssistantFromMsgs(msgs); got != "final after tool" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestEinoExtractFallbackAssistantFromMsgs_doesNotUseAssistantBeforeUnfinishedToolResult(t *testing.T) {
+	msgs := []*schema.Message{
+		schema.UserMessage("hi"),
+		schema.AssistantMessage("I will inspect that.", nil),
+		schema.AssistantMessage("", []schema.ToolCall{{
+			ID:   "call-1",
+			Type: "function",
+			Function: schema.FunctionCall{
+				Name:      "execute",
+				Arguments: `{"command":"pwd"}`,
+			},
+		}}),
+		schema.ToolMessage("/tmp", "call-1", schema.WithToolName("execute")),
+	}
+	if got := einoExtractFallbackAssistantFromMsgs(msgs); got != "" {
+		t.Fatalf("got %q, want empty", got)
+	}
+}
+
+func TestEinoRunResultBuilderFinalFallsBackToPlainAssistantTrace(t *testing.T) {
+	runMessages := newEinoRunMessageAccumulator(nil)
+	runMessages.Append(schema.UserMessage("hi"))
+	runMessages.Append(schema.AssistantMessage("plain answer", nil))
+
+	got := newEinoRunResultBuilder(einoRunResultBuilderConfig{
+		OrchMode:    "deep",
+		EmptyHint:   "empty",
+		RunMessages: runMessages,
+	}).BuildFinal()
+
+	if got.Response != "plain answer" {
+		t.Fatalf("response = %q, want plain answer", got.Response)
+	}
+}
+
 func toolExitMsg(content, callID string) *schema.Message {
 	m := schema.ToolMessage(content, callID)
 	m.ToolName = "exit"

internal/multiagent/eino_run_message_accumulator.go

@@ -57,6 +57,16 @@ func (a *einoRunMessageAccumulator) Messages() []adk.Message {
 	return a.msgs
 }
 
+func (a *einoRunMessageAccumulator) NewMessages() []adk.Message {
+	if a == nil {
+		return nil
+	}
+	if a.baseCount < 0 || a.baseCount >= len(a.msgs) {
+		return nil
+	}
+	return a.msgs[a.baseCount:]
+}
+
 func (a *einoRunMessageAccumulator) BaseCount() int {
 	if a == nil {
 		return 0

internal/multiagent/eino_run_message_accumulator_test.go

@@ -27,6 +27,10 @@ func TestEinoRunMessageAccumulatorTracksBaseAndAppends(t *testing.T) {
 	if len(msgs) != 2 || msgs[1].Role != schema.Assistant || msgs[1].Content != "hello" {
 		t.Fatalf("messages = %#v", msgs)
 	}
+	newMsgs := acc.NewMessages()
+	if len(newMsgs) != 1 || newMsgs[0].Content != "hello" {
+		t.Fatalf("new messages = %#v", newMsgs)
+	}
 }
 
 func TestEinoRunMessageAccumulatorToolMessage(t *testing.T) {

internal/multiagent/eino_run_result_builder.go

@@ -45,7 +45,7 @@ func (b *einoRunResultBuilder) BuildFinal() *RunResult {
 func (b *einoRunResultBuilder) build(partial bool) *RunResult {
 	var runMsgs []adk.Message
 	if b.cfg.RunMessages != nil {
-		runMsgs = b.cfg.RunMessages.Messages()
+		runMsgs = b.cfg.RunMessages.NewMessages()
 	}
 	var lastAssistant string
 	var lastPlanExecuteExecutor string
@@ -107,6 +107,9 @@ func buildEinoRunResultFromAccumulated(
 	if cleaned == "" {
 		if fb := strings.TrimSpace(einoExtractFallbackAssistantFromMsgs(runAccumulatedMsgs)); fb != "" {
 			cleaned = fb
+			if orchMode == "plan_execute" {
+				cleaned = UnwrapPlanExecuteUserText(cleaned)
+			}
 		}
 	}
 	cleaned = dedupeRepeatedParagraphs(cleaned, 80)
@@ -146,32 +149,38 @@ func markModelFacingTraceForPersistence(msgs []adk.Message) []adk.Message {
 	return out
 }
 
-// einoExtractFallbackAssistantFromMsgs 在「主通道未产出助手正文」时，从 Eino ADK 轨迹中回填用户可见回复。
-// 典型场景：监督者仅调用 exit（final_result 落在 Tool 消息中），或工具结果已写入历史但 lastAssistant 未更新。
+// einoExtractFallbackAssistantFromMsgs 在「主通道未产出助手正文」时，从 Eino ADK
+// 原生消息轨迹中回填用户可见回复。这里保持克制：只采纳倒序最近的可交付终态，
+// 避免把工具调用前的过渡语或子任务过程误升为最终回复。
 //
-// 优先级：最后一次 exit 工具输出 → 最后一条含 exit 的助手 tool_calls 参数中的 final_result。
+// 可交付终态：
+// - exit 工具输出；
+// - assistant 调用 exit 时 arguments.final_result；
+// - 没有后续普通工具结果截断的纯 assistant 正文。
 func einoExtractFallbackAssistantFromMsgs(msgs []adk.Message) string {
 	for i := len(msgs) - 1; i >= 0; i-- {
 		m := msgs[i]
-		if m == nil || m.Role != schema.Tool {
+		if m == nil {
 			continue
 		}
-		if !strings.EqualFold(strings.TrimSpace(m.ToolName), adk.ToolInfoExit.Name) {
-			continue
-		}
-		content := strings.TrimSpace(m.Content)
-		if content == "" || strings.HasPrefix(content, einomcp.ToolErrorPrefix) {
-			continue
-		}
-		return content
-	}
-	for i := len(msgs) - 1; i >= 0; i-- {
-		m := msgs[i]
-		if m == nil || m.Role != schema.Assistant {
-			continue
-		}
-		if s := einoExtractExitFinalFromAssistantToolCalls(m); s != "" {
-			return s
+		switch m.Role {
+		case schema.Tool:
+			if strings.EqualFold(strings.TrimSpace(m.ToolName), adk.ToolInfoExit.Name) {
+				content := strings.TrimSpace(m.Content)
+				if content != "" && !strings.HasPrefix(content, einomcp.ToolErrorPrefix) {
+					return content
+				}
+			}
+			return ""
+		case schema.Assistant:
+			if s := einoExtractExitFinalFromAssistantToolCalls(m); s != "" {
+				return s
+			}
+			if len(m.ToolCalls) == 0 {
+				if content := strings.TrimSpace(m.Content); content != "" {
+					return content
+				}
+			}
 		}
 	}
 	return ""

internal/multiagent/eino_run_result_builder_test.go

@@ -55,6 +55,24 @@ func TestEinoRunResultBuilderFinalUsesSnapshots(t *testing.T) {
 	}
 }
 
+func TestEinoRunResultBuilderFallbackIgnoresBaseHistory(t *testing.T) {
+	runMessages := newEinoRunMessageAccumulator([]adk.Message{
+		schema.UserMessage("previous request"),
+		schema.AssistantMessage("previous answer", nil),
+		schema.UserMessage("new request"),
+	})
+
+	got := newEinoRunResultBuilder(einoRunResultBuilderConfig{
+		OrchMode:    "deep",
+		EmptyHint:   "empty",
+		RunMessages: runMessages,
+	}).BuildFinal()
+
+	if got.Response != "empty" {
+		t.Fatalf("response = %q, want empty hint", got.Response)
+	}
+}
+
 func TestEinoRunResultBuilderPlanExecutePrefersExecutorOutput(t *testing.T) {
 	runMessages := newEinoRunMessageAccumulator(nil)
 	runMessages.Append(schema.AssistantMessage(`{"response":"planner text"}`, nil))
@@ -73,3 +91,18 @@ func TestEinoRunResultBuilderPlanExecutePrefersExecutorOutput(t *testing.T) {
 		t.Fatalf("response = %q, want executor text", got.Response)
 	}
 }
+
+func TestEinoRunResultBuilderPlanExecuteUnwrapsFallbackAssistant(t *testing.T) {
+	runMessages := newEinoRunMessageAccumulator(nil)
+	runMessages.Append(schema.AssistantMessage(`{"response":"fallback executor text"}`, nil))
+
+	got := newEinoRunResultBuilder(einoRunResultBuilderConfig{
+		OrchMode:    "plan_execute",
+		EmptyHint:   "empty",
+		RunMessages: runMessages,
+	}).BuildFinal()
+
+	if got.Response != "fallback executor text" {
+		t.Fatalf("response = %q, want fallback executor text", got.Response)
+	}
+}