Why should we think before we act (explain)?

In the great gatsby, daisy is described as

Match each feature of an investment with the correct investment. maturity date limited partner closing price flipping the amount a stock ended at for the day arrowright investing in a business without running it arrowright fixing up a property to sell it for a profit arrowright the date the bond expires and the principal is due arrowright

In describing jimmy wells as the truest, most loyal fellow, what tone is conveyed