Fix unmarshalling issues and adjust logging for debugging

Modify `FunctionCall` struct to handle arguments as strings. Add debugging logs to facilitate error tracing and improve JSON unmarshalling in various functions.

anthropic.go

@@ -2,6 +2,7 @@ package go_llm
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	anth "github.com/liushuangls/go-anthropic/v2"
 	"log"
@@ -120,13 +121,18 @@ func (a anthropic) responseToLLMResponse(in anth.MessagesResponse) Response {
 
 		case anth.MessagesContentTypeToolUse:
 			if msg.MessageContentToolUse != nil {
-				choice.Calls = append(choice.Calls, ToolCall{
-					ID: msg.MessageContentToolUse.ID,
-					FunctionCall: FunctionCall{
-						Name:      msg.MessageContentToolUse.Name,
-						Arguments: msg.MessageContentToolUse.Input,
-					},
-				})
+				b, e := json.Marshal(msg.MessageContentToolUse.Input)
+				if e != nil {
+					log.Println("failed to marshal input", e)
+				} else {
+					choice.Calls = append(choice.Calls, ToolCall{
+						ID: msg.MessageContentToolUse.ID,
+						FunctionCall: FunctionCall{
+							Name:      msg.MessageContentToolUse.Name,
+							Arguments: string(b),
+						},
+					})
+				}
 			}
 		}