Fuse dimensioning guidelines
The first thing to ask yourself is what exactly you mean by "protect the system against short circuit". Presumably you must protect the wiring, and prevent it from causing a hazardous condition if there is a short. If you intend to protect the motor from overload (eg. stalling) then you will have a somewhat different requirement. Fuses (even non-slo-blo types) can take quite a while to open up with a moderate overload. Or they can open early if they get too hot. They are not precision devices. 

If you are using a solid state device to switch the motor, chances are good that it will fail if a short circuit occurs well before the fuse opens. A brief short circuit could result in a continuously conducting transistor (or a welded relay) and the motor never shutting off. Protecting a semiconductor with a fuse is usually an expensive and often troublesome task. 

Motors draw a surge when starting up and that can blow the fuse immediately, or just weaken it gradually so it fails after some number of cycles. Test for this!

Finally, fuses work by dissipating power, so you will lose a bit of voltage in the fuse in normal operation. Make sure it is not too much for your circuit to work well. This is particularly important with low DC voltages. 

Your 2A slo-blo sounds reasonable, devoid of any other information, but it may be too low. You don't necessarily derive any benefit from calling it close. If the wiring can take 10A and the transistor will be dead anyway, a 5A fuse may be just as effective.