Chip lights
Some companies have fuzz burners which get rid of small particles and give the pilot an indication as to how serious the chip is while Aerospatial/Eurocopter had a system of measuring the area of debris and changing the box when the limit was reached. Again on a PT6 combining gear box I have had a chip warning that was due to an entire tooth coming off that was so big it prevented the self sealing on the chip detector closing but had no other obvious effect,ie vibration or oil pressure changes so take your pick but landing promptly seems a good idea.