There is no any website or tool which doing that. I think cipsoft can check how many items is in tibia but I don't think they are doing that. For example they even know how many steps made each character on fire etc. I know that because I wrote an email to cipsoft with a question about my main character when I was doing firewalker achievement. They easily answered me how many steps I did on all floors - underwater/swimming/fire.
We can know how many rare items are in Tibia only by seeing it in public. Sometimes on the websites like TibiaFandom it's written how many of items were made. EXAMPLE
Congrats shawtay on 10,000 reputation points!!!September 15, 2020
Outstanding Contribution contestSeptember 14, 2020
Hints for posts that received a down-voteAugust 15, 2020
I've received a down-vote - how can I fix it?August 14, 2020