I seem to be a magnet for the "Boat that needs help" , I.ve towed dozens of people. And I've come to a few conclusions. Typically the boat that needs help is skippered by someone that simply isn't prepared. Sure there are mechanical failures, etc.. That can't be helped but it's usually - out of gas, or I didn't check battery, or I didn't watch the weather. Now a days I start with " throw me your tow line "and that will tell you in a second who you are dealing with. I've been handed 6 foot shoe strings that they expected to do the job.
Your first concern is are they safe and heathy, second is get them out of the way of other boat traffic. Then there is the issue of how far are you going to tow them. It's really slow going. Short runs no big deal but I've tied up to people that thought I was going to tow them18 miles... I'll drag you to to the nearest ramp, you beach your boat, you are safe and dry and you can make calls to solve your problem. I know that sounds cold but you can get sucked into all afternoon ordeals on some fools errand. Be safe, Think ahead.