Quick question! Sign of acceleration

In a pulley system, with one end attached to an object of mass M and the other end being held by an external agent. When the external agent pulls the string, the object moves upward.

I am confused whether the acceleration of the object will have a negative or positive sign?

Thanks,
Chris

The weight of an object is always directed downward.

I say the direction of the initial motion is positive. When the external agent pulls the string, the object moves upward, so upward motion is positive. The object has 2 forces, tension up and weight down.

Tension is positive and weight is negative.
Net force = Tension – Weight = mass * acceleration
Acceleration = Net force ÷ mass

Since the object moves upward, the tension must be greater than the weight. So the net force is positive. So, the acceleration is positive.