Per this documentation, the maximum length of a field name in a .gdb is 64 characters. However, users are capped at 29 characters when setting up a new field in the Fields view. I cannot enter any more characters here:

Yet GP tools output field names that are, in fact, longer than 29 characters:

When you enter that cell and tap any key, all of a sudden you're over the limit and can no longer save even though you didn't actually change anything.

Please walk the walk on your documentation, thanks.