EDB migration toolkit is good for data objects when the target is community PostgreSQL. It won't be migrating code objects like procedures, packages, functions etc. For PostgreSQL target one may opt Ora2pg.
If your target is EDB Postgres then EDB Migration toolkit is good and even better is EDB's Migration Portal for schema migration, as it leverages to correct DDLs online and reassess if these fail after Assessment and conversion by Portal. Again for data you will have to use EDB Migration toolkit.