How to view the table structure in DB2 database
The OP doesn't mention if this is DB2/400 being discussed, but I found that the only way I could get the table structure including the column name descriptions was to use DSPFFD.
DSPFFD FILE(TBNAME) OUTPUT(*OUTFILE) OUTFILE(SOMELIB/TBDESC)
This puts the description of TBNAME in a table called TBDESC in the SOMELIB library. You can then query that with:
select * from SOMELIB/TBDESC