sqlite3 and cursor.description
No, it's not the only way. Alternatively, you can also fetch one row, iterate over it, and inspect the individual column Python objects and types. Unless the value is None (in which case the SQL field is NULL), this should give you a fairly precise indication what the database column type was.
sqlite3 only uses sqlite3_column_decltype and sqlite3_column_type in one place, each, and neither are accessible to the Python application - so their is no "direct" way that you may have been looking for.
I haven't tried this in Python, but you could try something like
SELECT *FROM sqlite_masterWHERE type = 'table';which contains the DDL CREATE statement used to create the table. By parsing the DDL you can get the column type info, such as it is. Remember that SQLITE is rather vague and unrestrictive when it comes to column data types.