You could offer gardening tools for reuse by a local school or gardening club. They may be suitable for reuse through a local reuse network such as Freecycle or Freegle. There are now a large number of reuse groups on Facebook.
If they need sharpening, your nearest Repair Café is able to do this for a small donation.
Otherwise these can be taken to a local Household Recycling Centre where they may be suitable for recycling in the scrap metal container (depending what they are made from) – please ask a member of staff for advice when you arrive at the site.