the power on a 3x9 with 36 to 40mm obj. will do just fine on shots out to 300 yards,after that it may be hard to define the actual size of the animal you are looking at and it may be difficult to judge how high to shoot on a real long shot.so to answere your question you should be fine.
When calling coyotes, more often than not they will circle on a target they are
coming into and approach from the downwind side. Presumably they do this in
order to align what they smell, with what they are hearing.
This means that you should always have your downwind side camouflaged and have
an open shooting lane. If the area is heavily covered the coyote could come in
take a look and be gone, with you none the wiser.