In the VM the attach logic sets limits on the number and types of arguments that can be received:

class AttachOperation: public CHeapObj<mtInternal> {
 public:
  enum {
    name_length_max = 16,       // maximum length of  name
    arg_length_max = 1024,      // maximum length of argument
    arg_count_max = 4           // maximum number of arguments
  };

but the client tools that send these requests may include arbitrary length arguments, such as filenames, that might exceed these limits.