The “right” way to do stored procedure parameter validation

Question

I have a stored procedure that does some parameter validation and should fail and stop execution if the parameter is not valid.

My first approach for error checking look

Answer 1

We normally avoid raiseerror() and return a value that indicates an error, for example a negative number:

if 
    return -1

Or pass the result in two out parameters:

create procedure dbo.TestProc
    ....
    @result int output,
    @errormessage varchar(256) output
as
set @result = -99
set @errormessage = null
....
if 
    begin
    set @result = -1
    set @errormessage = 'Condition failed'
    return @result
    end