V$SQLFN_ARG_METADATA contains metadata about function arguments. There is one row for each argument of every function found in V$SQLFN_METADATA. There are no rows for functions that do not have any arguments.

Column Datatype Description
FUNC_ID NUMBER Internal function identification number. This column can be used to join with the V$SQLFN_METADATA view.
ARGNUM NUMBER Argument number
DATATYPE VARCHAR2(8) Datatype of the argument. The value is NULL if this argument is not used. Otherwise, it can take values of any Oracle datatype, family datatype, or EXPR datatype.
DESCR VARCHAR2(30) This column is reserved for future use.