Host Tools cannot sync with Furnished Finder in either direction. This is not a Host Tools limitation, it is down to what Furnished Finder currently supports.
Why Furnished Finder cannot be connected
There are two separate limits, and together they rule out both directions of a sync.
Furnished Finder does not offer an iCal export. There is no calendar link you can copy out of Furnished Finder, so there is nothing for Host Tools to import. Your Furnished Finder reservations cannot come into Host Tools.
Furnished Finder only accepts iCal imports from Airbnb and Vrbo. It will not accept a calendar link from anywhere else, so you cannot give Furnished Finder your Host Tools export link. Your Host Tools availability cannot go out to Furnished Finder.
How to keep your Furnished Finder calendar up to date
Because Furnished Finder does accept Airbnb and Vrbo calendars, you can still stop your Airbnb and Vrbo bookings from being double booked on Furnished Finder. Import those two calendars into Furnished Finder directly.
Copy your listing's iCal export link from Airbnb, and from Vrbo if you list there as well. These come from Airbnb and Vrbo themselves, not from Host Tools.
In Furnished Finder, open the calendar for the property and add each link as a calendar import.
Once that is set up, a booking taken on Airbnb or Vrbo will close those dates on Furnished Finder.
What this means for bookings taken on Furnished Finder
A booking made on Furnished Finder is the one case nothing can cover automatically. It will not reach Host Tools, and it will not reach Airbnb or Vrbo either, so those dates stay open everywhere else until you close them yourself.
When you take a Furnished Finder booking, add it to your Host Tools calendar manually. Host Tools will then block those dates on every channel you have connected, which prevents a double booking.
Two things to be aware of for manually added reservations:
There is no message thread with a Furnished Finder guest, so automated messages cannot be delivered through the channel. You can still send automated messages to manually added reservations by email or SMS.
Host Tools does not set prices on Furnished Finder. Your pricing rules only apply to the channels you have connected.
Channels Host Tools does connect to
Host Tools connects directly to Airbnb, Vrbo, Booking.com, Houfy and Google Vacation Rentals, and can import reservations from any other site that publishes an iCal link. Here is how to add an iCal link from a channel we do not integrate with. Furnished Finder does not publish one, which is why it cannot be added this way.