Actually, a minimal magnet link only contains the infohash which "points" at just the info section of the torrent file. The info section contains the name, list

Actually, a minimal magnet link only contains the infohash which "points" at just the info section of the torrent file. The info section contains the name, list of files and SHA1 hashes for all pieces, and the private flag. The trackers are outside of info section, I assume so the list of trackers can be modified without effecting the info hash. Though, some magnet links include an optional xs parameter which points at an http url containing the .torrent file, which would include the trackers. In my experience, you don't receive the trackers from other peers (though maybe other bittorrent clients can?). However, if at least one peer you discover via DHT supports the peer exchange protocol, and has the trackers, your client can quickly query all the relevant peers.