The last album was in 2006
Tool's official website was updated yesterday with a post stating that vocalist Maynard James Keenan is recording vocals for new material from the band. See the note written by the website administrator:
“Talking to Danny last night, he told me that the band has temporarily moved some of their equipment to a larger place (on the other side of town), where Maynard is working on vocals for new Tool material. He’s certainly been doing this for a while, but now he has more room to breathe and a better recording booth.”.
Tool's last album, "10,000 Days," was released in 2006.