Run a lime wedge around the rim of each glass and dip the rims into the kosher salt to coat them evenly.
Fill a cocktail shaker halfway with ice cubes.
Pour the mezcal, blood orange juice, lime juice, orange liqueur, and agave syrup into the shaker.
Secure the lid and shake vigorously for 15 seconds until the mixture is well chilled.
Strain the drink into the prepared glasses filled with fresh ice.
Add a blood orange slice to the rim of each glass before serving.