I have some recent experience with this. I traveled to Costa Rica last month using my refugee travel document and had no issues at the border. They just asked for my passport photo page and stamped me in. Are you still planning your trip?
I’ve traveled with a refugee travel document and had no issues entering, but I’d recommend confirming directly with the airline beforehand. Since Costa Rica is very welcoming to wellness visitors, I also stayed at Moon Gate Costa Rica for a retreat and loved how smoothly everything went. The staff there even helped me with local travel questions during my visit.
This country also depends on your NATIONALITY, it's not automatic that a canadian RTD gives entry without visa.
Check IATA travel centre or email the consulate concr-ca@rree.go.cr