Event class description not showing

The Event IDs and descriptions are found in sys.trace_events

One option could be to join to this catalog view when querying the trace data.

When using the Profiler UI, the translation is made for you - not sure you can make the trace store the actual descriptions.

Quick and dirty way to deal with this is to create a view, similar to:

CREATE VIEW VerboseLog
AS
  SELECT tc.Name AS TraceCategory,
        te.Name AS TraceEvent,
        l.*
  FROM   **TraceTableName** l
        LEFT JOIN sys.trace_events te
          ON l.EventClass = te.trace_event_id
        LEFT JOIN sys.trace_categories tc
          ON te.category_id = tc.category_id;

Of course, you may want to trim the columns down a bit...