The reason it is important to read the fine print is because the dreaded asterisk may reveal that your lost-luggage coverage may exclude items such as sunglasses, medications, and car keys. Or your delayed-baggage coverage may only reimburse you for $50 worth of items if your baggage doesn't get to you in time—which doesn't go far if you're stuck in Zurich with only the clothes on your back.
A good resource is InsureMyTrip.com, which provides summaries of dozens of insurance policies.
Some credit cards also cover trips paid for with the card, and they automatically offer coverage for lost bags, roadside assistance, and medical care for some injuries. Other cards let you buy coverage on a per-trip basis. But the same rule applies: Read the fine print.