I recall reading somewhere that there is a free shuttle between the St-Pierre-des-Corps and Tours train stations, which also goes into the Old Town in Tours, but can't seem to find any info online now. Is anyone aware of this option? If not, we'll either do the short train ride from St-Pierre-des-Corps to Tours, or just take a taxi from there right to our hotel.
The difference between the two stations is only about 2 km. You should be able to book to Tours Centre with any arrival at St Pierre des Corps. The shuttle is a train that travels the 5 minutes between the two stations and runs regularly.
It's not free, and it's not always a shuttle. Most (if not all) trains that don't go on to Tours are met by a train, it might be a shuttle, but it could equally just be another train.