Grouping out parameters into a struct

Question

I have a function with a large number of out parameters which currenly looks as

int do_some_foo(char **string_out, int *index_out, char **description_out, etc...);

So since out parameters may grow and currently already about 8 in total (some of them omitted for brevity) I tend to group all the parameters into a struct and document that the caller does not own the out pointers

struct foo_out{
    int status;
    char *string;
    int index;
    char *description;
    //...
};

//Pointers contained in the return value are not owned by
//the caller and should not be modified or reclaimed by it in 
//any way
const struct foo_out *do_some_foo(int *error_code);

//Release all the resources used by the library
//all const struct foo_out * pointers returned by do_some_foo
//becomes invalid
void prepare_shutdown(void);

By this way I think I restricted the called from using this pointer after releasing resources used by the library. So the caller is not supposed to use the pointers after calling to it.