test: Introduce comprehensive edge case tests across multiple modules and refine tool call and OpenAI handler logic.

internal/util/toolcalls.go

@@ -41,6 +41,9 @@ func ParseStandaloneToolCalls(text string, availableToolNames []string) []Parsed
 	if trimmed == "" {
 		return nil
 	}
+	if looksLikeToolExampleContext(trimmed) {
+		return nil
+	}
 	candidates := []string{trimmed}
 	if strings.HasPrefix(trimmed, "```") && strings.HasSuffix(trimmed, "```") {
 		if m := fencedJSONPattern.FindStringSubmatch(trimmed); len(m) >= 2 {
@@ -313,6 +316,30 @@ func extractJSONObject(text string, start int) (string, int, bool) {
 	return "", 0, false
 }
 
+func looksLikeToolExampleContext(text string) bool {
+	t := strings.ToLower(strings.TrimSpace(text))
+	if t == "" {
+		return false
+	}
+	cues := []string{
+		"```",
+		"示例",
+		"例子",
+		"for example",
+		"example",
+		"demo",
+		"请勿执行",
+		"不要执行",
+		"do not execute",
+	}
+	for _, cue := range cues {
+		if strings.Contains(t, cue) {
+			return true
+		}
+	}
+	return false
+}
+
 func FormatOpenAIToolCalls(calls []ParsedToolCall) []map[string]any {
 	out := make([]map[string]any, 0, len(calls))
 	for _, c := range calls {

internal/util/toolcalls_test.go

@@ -75,3 +75,10 @@ func TestParseStandaloneToolCallsOnlyMatchesStandalonePayload(t *testing.T) {
 		t.Fatalf("expected standalone parser to match, got %#v", calls)
 	}
 }
+
+func TestParseStandaloneToolCallsIgnoresFencedCodeBlock(t *testing.T) {
+	fenced := "```json\n{\"tool_calls\":[{\"name\":\"search\",\"input\":{\"q\":\"go\"}}]}\n```"
+	if calls := ParseStandaloneToolCalls(fenced, []string{"search"}); len(calls) != 0 {
+		t.Fatalf("expected fenced tool_call example to be ignored, got %#v", calls)
+	}
+}