"Will we tell?"
Only first conjugation verbs have future suffixes that begin with an F — viz -faimid or -fimid in the synthetic second person plural. Their second conjugation analogues have -óimid or -eoimid instead.
I've noticed in general that the hover-over hints for verbs in future-tense questions aren't correct. Here it seems to read it as "we tell" and gives "insímid" accordingly.