It's deliberate that \dt doesn't show toast tables.
\d shows them, but doesn't show their indices.
It seems to me that their indices should be shown, without having to think and
know to query pg_index.
postgres=# \d pg_toast.pg_toast_2600
TOAST table "pg_toast.pg_toast_2600"
Column | Type
------------+---------
chunk_id | oid
chunk_seq | integer
chunk_data | bytea
Indexes:
"pg_toast_2600_index" PRIMARY KEY, btree (chunk_id, chunk_seq)
Justin