You've seen this before. A website that somewhere in the nav (perhaps a utility nav) has the labels tools and resources.
What do you expect to find behind each label? I feel that many sites use these two labels interchangeably to mean the same thing.
IMO, Resources should be the label if the stuff behind it contains guides, research, links to other articles, website links, glossaries, etc.
Tools should be the label if the stuff behind it contains "things" to get work done or accomplish a task – some piece of functionality.