To Find Parameter Data Type Size

CREATE PROC [dbo].[PARAMETERS_TYPES_SIZES]

AS

BEGIN

            SELECT PR.NAME,PA.NAME,TY.NAME+

                                    CASE WHEN TY.NAME IN ('int','smallint','bigint','bit','datetime','money','tinyint') 

                                    THEN '' 

                                    ELSE '('+cast(PA.max_length as varchar(100))+')' END as SIZE

            FROM SYS.PROCEDURES PR

                        JOIN  SYS.PARAMETERS PA

            ON PR.OBJECT_ID=PA.OBJECT_ID

                        JOIN SYS.TYPES TY

            ON PA.USER_TYPE_ID=TY.USER_TYPE_ID

END

exec  PARAMETERS_TYPES_SIZES

output:
NAME                 NAME                         SIZE

Sp_Proc               @parameterName        Varchar(100)