The documentation states:

more_itertools.strictly_n(iterable, n, too_short=None, too_long=None)
Validate that iterable has exactly n items and return them if it does.
If it has fewer than n items, call function too_short with those items. If it has more than n items, call function too_long with the first n + 1 items.

However, as the [source] shows:

    if sent < n:
        too_short(sent)
        return

    for item in it:
        too_long(n + 1)
        return

the documentation should read:

...
If it has fewer than n items, call function too_short with the item-count of those items. If it has more than n items, call function too_long with the number n + 1.

The provided examples also demonstrate that the functions receive counts, not items.