Here are some things to note: If the episode count is lower than on MAL nothing is changed. Specials and OVAs are not yet supported.
More complex things like long running Shōnen shows with absolute numbering or Movies releases that actually are multiple OVAs are also not included.
Ratings will all be overwritten to as they're on trakt (if rated there). If no season ratings are available it will fallback to the show rating.
Your profile also has to be set to public on trakt.tv.
Please be patient as the script will take a little while to complete.
Subsequent runs will complete faster :). If you have a lot of data and are a first time user consider running it more than once (MAL's rate limiting still catches some pushes unfortunately).
For reference the current index of titles that can be synced:
Instead looking for a way to import your MAL profile into trakt? Then check out the Import script!
Want MAL links on trakt? Install this.
Looking to automate? Have a look here.
Noticed a problem? Just let me know and I'll try to fix it!