You know, when it comes to going to a mission you should be given a bit more detail on the site so you can better prepare. Like you couldn’t see a crab monster the size of a building before landing. The haven could certainly tell you what the forces are like that are approaching or attacking them. It’s called a SALUTE in the army.
SALUTE - observation of/contact with enemy; Size, Activity, Location, Unit/uniform, Time, Equipment.