translator: add nil checks for tool call ids before dereferencing the pointers

internal/translator/anthropic_helper.go

@@ -429,6 +429,10 @@ func openAIMessageToAnthropicMessageRoleAssistant(openAiMessage *openai.ChatComp
 	// Handle tool_calls (if any).
 	for i := range openAiMessage.ToolCalls {
 		toolCall := &openAiMessage.ToolCalls[i]
+		if toolCall.ID == nil {
+			err = fmt.Errorf("%w: tool_call at index %d is missing required field 'id'", internalapi.ErrInvalidRequestBody, i)
+			return
+		}
 		var input map[string]any
 		if err = json.Unmarshal([]byte(toolCall.Function.Arguments), &input); err != nil {
 			err = fmt.Errorf("failed to unmarshal tool call arguments: %w", err)

internal/translator/gemini_helper.go

@@ -277,6 +277,9 @@ func assistantMsgToGeminiParts(msg *openai.ChatCompletionAssistantMessageParam)
 	// Handle tool calls in the assistant message.
 	knownToolCalls := make(map[string]string)
 	for i, toolCall := range msg.ToolCalls {
+		if toolCall.ID == nil {
+			return nil, nil, fmt.Errorf("%w: tool_call at index %d is missing required field 'id'", internalapi.ErrInvalidRequestBody, i)
+		}
 		knownToolCalls[*toolCall.ID] = toolCall.Function.Name
 		var parsedArgs map[string]any
 		if err := json.Unmarshal([]byte(toolCall.Function.Arguments), &parsedArgs); err != nil {

internal/translator/openai_awsbedrock.go

@@ -414,6 +414,9 @@ func (o *openAIToAWSBedrockTranslatorV1ChatCompletion) openAIMessageToBedrockMes
 
 	for i := range openAiMessage.ToolCalls {
 		toolCall := &openAiMessage.ToolCalls[i]
+		if toolCall.ID == nil {
+			return nil, fmt.Errorf("%w: tool_call at index %d is missing required field 'id'", internalapi.ErrInvalidRequestBody, i)
+		}
 		input, err := unmarshalToolCallArguments(toolCall.Function.Arguments)
 		if err != nil {
 			return nil, err