refactor: enhance AgentLoopEngine with confirmed MCP reply handling and add tests for tool result summarization

internal/ai/runtime/tooling/tool_result_reducer.go

@@ -98,5 +98,27 @@ func appendNonBlankSegment(input []string, value string) []string {
 	if value == "" {
 		return input
 	}
+	key := canonicalToolResultSegment(value)
+	for _, existing := range input {
+		if canonicalToolResultSegment(existing) == key {
+			return input
+		}
+	}
 	return append(input, value)
 }
+
+func canonicalToolResultSegment(value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return ""
+	}
+	var payload any
+	if err := json.Unmarshal([]byte(value), &payload); err != nil {
+		return value
+	}
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return value
+	}
+	return string(data)
+}

internal/ai/runtime/tooling/tool_result_reducer_test.go

@@ -0,0 +1,44 @@
+package tooling
+
+import (
+	"strings"
+	"testing"
+
+	"agent-desk/internal/ai/mcps"
+)
+
+func TestBuildReducedToolResultSummaryDeduplicatesStructuredAndTextContent(t *testing.T) {
+	result := &mcps.ToolCallResult{
+		StructuredContent: map[string]any{
+			"timestamp": "2026-07-28 11:51:52",
+			"timezone":  "Local",
+		},
+		Content: []mcps.ToolResultContent{{
+			Type: "text",
+			Text: `{"timezone":"Local","timestamp":"2026-07-28 11:51:52"}`,
+		}},
+	}
+
+	summary := BuildReducedToolResultSummary(result)
+	if strings.Count(summary, "timestamp") != 1 {
+		t.Fatalf("duplicate MCP result was not removed: %q", summary)
+	}
+	if summary != `{"timestamp":"2026-07-28 11:51:52","timezone":"Local"}` {
+		t.Fatalf("unexpected reduced result: %q", summary)
+	}
+}
+
+func TestBuildReducedToolResultSummaryKeepsDistinctSegments(t *testing.T) {
+	result := &mcps.ToolCallResult{
+		StructuredContent: map[string]any{"status": "ok"},
+		Content: []mcps.ToolResultContent{{
+			Type: "text",
+			Text: "additional context",
+		}},
+	}
+
+	summary := BuildReducedToolResultSummary(result)
+	if !strings.Contains(summary, `{"status":"ok"}`) || !strings.Contains(summary, "additional context") {
+		t.Fatalf("distinct MCP result segments were lost: %q", summary)
+	}
+}