The Bard in my game knows the spell Unseen Servant, and I'm not sure of its limitations. The description of the spell says (PHB, p. 284):
This spell creates an invisible, mindless, shapeless force that
performs simple tasks at your command until the spell ends. […]
Once on each of your turns as a bonus action, you can mentally command
the servant to move up to 15 feet and interact with an object. The
servant can perform simple tasks that a human servant could do, such
as fetching things, cleaning, mending, folding clothes, lighting
fires, serving food, and pouring wine. Once you give the command, the
servant performs the task to the best of its ability until it
completes the task, then waits for your next command.
If you command the servant to perform a task that would move it more
than 60 feet away from you, the spell ends.
I have a few questions here:
- Can this mindless force scout around a corner and report back what it
sees? This task seems like a "simple task that a human servant could
do", but I'm not sure if this servant can communicate.
- If it can scout in this way, I presume it doesn't have darkvision; is
that correct? I don't see why it would, and it isn't specified that
it does, but I figure I'd check.
- If it can scout and communicate, would it communicate back to its
Bard master telepathically the way that the Bard communicates with
"Mindless" is probably the limiting factor for this problem. How a mindless servant reacts to this kind of command is simple, really. Imagine how another mindless creature, such as a servant zombie, would react.
Unfortunately, I do not see a servant zombie walking ahead, peeking around the corner, and then calling out "I see three orcs and a goblin, my master!" It is unable to communicate the results back to you!
You might be able to get it to communicate some simple results. The command "If a creature is around the corner pick up that pebble and hand it to me" would likely be successful, but if he handed you the pebble you have no way of knowing if the 'creature' was a rat or an ogre.