"O be wise; what can I say more?"
The American Heritage College Dictionary defines wise as: Having the ability to discern or judge what is true, right, or lasting; sagacious.
In proverbs, wisdom is described as being "better than rubies." And the person who obtains wisdom "loveth his own soul." The Lord tells his modern-day people to "seek not for riches but for wisdom."
So, reasonably, if we have wisdom, we are wise, and if we are wise, we have the ability to recognize truth and right.
Notice that Jacob does not tell us to have wisdom; he tells us to be wise, implying an action on our part. Obtaining wisdom is important, but it does us no good unless we use the wisdom we have gained to make correct choices and draw closer to our Heavenly Father.
I love that the gospel of Jesus Christ can be so simple: get the ability to judge those things that are true and right, and then use it. Jacob is right; what can he say more?