Snowflake procedures do not have OUT or INOUT parameters. Instead, the result is returned as either a single value or as a table. In both cases, the result is shown in the data grid.
Due to a problem with the Snowflake ODBC Driver, AQT needs to specify parameter values twice. You will notice this when you use Copy to SQL window and see the SQL that AQT uses for running the procedure.
This problem may be corrected in later versions of the Snowflake ODBC Driver.