fix: support raw JSON response tool arguments

common/json.go

@@ -43,3 +43,19 @@ func GetJsonType(data json.RawMessage) string {
 		return "number"
 	}
 }
+
+// JsonRawMessageToString returns JSON strings as their decoded value and other JSON values as raw text.
+func JsonRawMessageToString(data json.RawMessage) string {
+	trimmed := bytes.TrimSpace(data)
+	if len(trimmed) == 0 || bytes.Equal(trimmed, []byte("null")) {
+		return ""
+	}
+	if trimmed[0] != '"' {
+		return string(trimmed)
+	}
+	var value string
+	if err := Unmarshal(trimmed, &value); err != nil {
+		return string(trimmed)
+	}
+	return value
+}

common/json_test.go

@@ -0,0 +1,43 @@
+package common
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestJsonRawMessageToString(t *testing.T) {
+	tests := []struct {
+		name string
+		data json.RawMessage
+		want string
+	}{
+		{
+			name: "object",
+			data: json.RawMessage(`{"city":"Paris","days":0,"strict":false}`),
+			want: `{"city":"Paris","days":0,"strict":false}`,
+		},
+		{
+			name: "string",
+			data: json.RawMessage(`"{\"city\":\"Paris\",\"days\":0,\"strict\":false}"`),
+			want: `{"city":"Paris","days":0,"strict":false}`,
+		},
+		{
+			name: "null",
+			data: json.RawMessage(`null`),
+			want: "",
+		},
+		{
+			name: "empty",
+			data: nil,
+			want: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, JsonRawMessageToString(tt.data))
+		})
+	}
+}