What is the ruling on benefiting from tools whose owner is unknown, that have been left in the college for years, and are not inquired about?

If it is highly probable that the owner of the tools left them by mistake, then they are a Luqatah (found item) that must be kept and announced for a year. After that, the finder may take possession of them, while guaranteeing their value to the owner should he be found. However, if it is an insignificant item that its owner would not care to pursue, then the finder may benefit from it without announcing it. And if the evidence indicates that its owner abandoned it out of disinterest, then there is no harm in taking and possessing it, acting upon what Ibn al-Qayyim stated regarding the consideration of circumstantial evidence in Islamic law. This includes taking what people discard out of disinterest.