Here's why:
* "Tutus" means safe or secure in Latin.
* "Prompto" is the adjective form of "promptus," meaning ready or prepared.
* "Animo" is the ablative singular of "animus," meaning mind or spirit.
While each word is valid, the combination doesn't form a common Latin phrase.
It's possible that the phrase is a deliberate combination meant to convey a specific meaning.
If you can provide more context or the source of this phrase, I might be able to offer a more accurate interpretation.