You need to use sp_describe_first_result_set
which is new to SQL Server 2012. Note that this requires you to provide the input parameters (at least the types).
In T-SQL development one is expected to know what procedures is calling and what is the expected result set. Before SQL server 2012 there was very little support for dynamic, runtime, discovery of procedure output and required parameters. This new procedure, along with others like sp_describe_undeclared_parameters
can be used to create tools that need to explore the available programming API surface. The very fact that these were added to 2012 should indicate that the equivalent cannot be properly handled pre-2012. Solutions like loopback linked servers have many problems, primarily because they actually execute the code with potential disastrous effects.