Thinking of changing jobs? Then be sure to take a careful look at 401(k) plans offered by any potential employers. It’s not just a matter of finding a plan that offers solid investment gains without too much risk: A 401(k) is a window into the boss’s inner nature.

Companies with good plans tend to serve their shareholders better than ones that don’t.

Even the most bare-bones 401(k) costs the boss something, and the price-tag can be very high for employers that match all or part of employees’ contributions.

“The purpose of these plans is to attract, retain and motivate high-quality workers. Employers are not offering these plans because they are philanthropic,” says David L. Wray, president of the Profit Sharing/401(k) Council of America, a nonprofit organization representing 1,200 employers with 6 million plan participants.

So what are the elements of a good plan?

The boss should match your contributions up to a level equal to at least 6 percent of your gross annual pay, and in cash that you decide how to invest.

The plan should offer at least a dozen mutual funds, including life-cycle funds, which automatically move to more conservative holdings as the employee ages.

Fees, such as “expense ratios” charged by the funds, should be very low – definitely less than 1 percent a year.

The plan also should provide easy-to-understand quarterly and annual statements, and offer good education and advice.