Need help to reuse old laptop harddisk

Device: 2.5" 500GB (5400rpm) Seagate internal hard disk from old Dell XPS 15 Laptop.

Problem: When connected to a PC through SATA connection it makes a continuous clicking noise. When googling the problem, I got across "Click of Death" article. It article says "The click of death may indicate that the hard drive has crashed or failed". But when I connect it to the laptop it boots into the OS and works fine.

I need some guidance in identifying the issue here.

I really can't tell you how to reuse it (in fact, I wouldn't advise it), but I would recommend getting all of your data off of it and cut your losses at that. The "Click of Death" doesn't necessarily mean that your hard drive is dead, but from the hard drives I've seen do this in my work environment, it may mean that drive death is imminent (I've seen drives die in a week and drives last through the machine's scheduled life cycle replacement). There could be a few different types of causes to this, so check this out and it might be able to help you -

A friend of mine has had the same problem and in the beginning he didn't care that much about that noise but than he started having difficulties to boot into the OS. I think the drive is getting to the point where it might fail soon. As Doctor_Briola righfully said save all the important data from it in a more reliable HDD.

Found out there was a fault in the power connector for the Hard Disk. Replaced a new cable and now it is working properly on my PC. I'm gonna make a backup just in cause.

That noise is almost never a good sign. Usually the drive is probably on its way out. The clicking you are hearing is more likely you reader head, and that is never a good sign.
Even if things seem okay, might still be going.
As for the drive itself, you can use a hd tester/bootable HD tester (hirens) to check the sectors on the drive for consistency. Drives go bad when the head goes, or even a speck of dust gets on the disc platter. If you still really want to use it, you can use a HD tester like WD diag to 'repair' it, but I wouldn't recommend it for anything important, as it basically just tells the drive to ignore those non-readable sectors.

What does the SMART status of the drive say?