diff --git a/pkg/bridge/ai/provider/anthropic/provider.go b/pkg/bridge/ai/provider/anthropic/provider.go
index 56eed5aa6..399ff9dc6 100644
--- a/pkg/bridge/ai/provider/anthropic/provider.go
+++ b/pkg/bridge/ai/provider/anthropic/provider.go
@@ -326,6 +326,7 @@ func (p *Provider) convertMessageNewParams(req openai.ChatCompletionRequest) ant
 		case openai.ChatMessageRoleAssistant:
 			// tool use, check if there are tool calls
 			if len(msg.ToolCalls) > 0 {
+				ylog.Debug("openai request", "tool_calls", len(msg.ToolCalls))
 				toolUses := make([]anthropic.ContentBlockParamUnion, 0)
 				for i, toolCall := range msg.ToolCalls {
 					ylog.Debug("openai request", "tool_calls", len(msg.ToolCalls))
diff --git a/pkg/bridge/ai/service_test.go b/pkg/bridge/ai/service_test.go
index 23a41de26..e50d106d5 100644
--- a/pkg/bridge/ai/service_test.go
+++ b/pkg/bridge/ai/service_test.go
@@ -51,12 +51,31 @@ func TestOpSystemPrompt(t *testing.T) {
 			args: args{
 				prompt: "",
 				op:     SystemPromptOpOverwrite,
-				req:    openai.ChatCompletionRequest{},
+				req: openai.ChatCompletionRequest{
+					Messages: []openai.ChatCompletionMessage{},
+				},
 			},
 			want: openai.ChatCompletionRequest{
 				Messages: []openai.ChatCompletionMessage{},
 			},
 		},
+		{
+			name: "empty system prompt should not overwrite",
+			args: args{
+				prompt: "",
+				op:     SystemPromptOpOverwrite,
+				req: openai.ChatCompletionRequest{
+					Messages: []openai.ChatCompletionMessage{
+						{Role: "system", Content: "hello"},
+					},
+				},
+			},
+			want: openai.ChatCompletionRequest{
+				Messages: []openai.ChatCompletionMessage{
+					{Role: "system", Content: "hello"},
+				},
+			},
+		},
 		{
 			name: "overwrite with not empty system prompt",
 			args: args{