I would like to know whether it is possible to instantiate a class in another system via RFC and then call a method eg. cl_abap_typedescr=>describe_by_name, of that class in the other system like you can with an RFC enabled function.
Its not possible to call a method like RFC.
What you could do is write a RFC and within that instantiate the class and call desired method .
And now you can call this RFC from the other system.