What it can look like at home
Short cycling is a pattern, not a homeowner diagnosis. The system may be stopping because airflow is restricted, a drain safety switch is interrupting operation, the thermostat is in a poor location, an electrical control is weak, refrigerant-side conditions are abnormal, or the equipment is not matched well to the home. On humid days, the house may feel cool for a moment but still damp because the system never runs long enough to remove moisture well. The important thing is not to force the thermostat lower and lower. The useful information is the timing: how often it starts, how quickly it stops, whether the outdoor unit runs. Also note whether the problem is worse during heat and humidity.
Why it can happen
Common short-cycling patterns can involve dirty filters, blocked returns, dirty coils, condensate drain safety switches, thermostat placement, control-board interruptions, weak contactors or capacitors, refrigerant-side problems, or equipment sizing. Capacitors, contactors, line voltage, and refrigerant are technician-only checks. A safe service visit looks at airflow, temperature split, drainage, controls, outdoor-unit behavior, and the sequence of operation instead of guessing from one symptom.