Agile is not a noun. Indeed, it does not signify a noun, i.e., a state of mental attitude towards your organization. You are constantly becoming agile. Agile is not a verb. You cannot do agile; incorporate a set of practices from the book.
Let’s suspend whether we should or should not be agile for a moment. And discuss what we mean when we use the term.
Refer to the following articles to delve into the topic.