I live in this area. There is no stop sign at that intersection normally.

Thank you for bringing this issue to our attention! One of our City of Marlborough Streets Division staff will take a look at the issue. Based on what we find when we investigate the issue, we will determine what course of action is required and schedule any necessary repairs. If we need further information we will contact you. Marlborough Public Works 508-624-6910

Public Works Dispatch assigned this issue to Street Division

I agree with MDS. I have been living two blocks away from this intersection for over 10 years and I have never seen a stop sign there. That being said, I think it would be prudent to have one installed.

This intersection is not controlled by a STOP sign, the normal "Rule of the Road" applies.
The MassDOT/RMV Vehicle Manual states:

For intersections not controlled by signs or signals;

Slow down at an uncontrolled intersection. Look left and right for oncoming traffic and proceed if the way is clear. However:
• You must yield the right-of-way to any vehicle that has entered the intersection from your right or is coming from your right.
• Look for traffic coming from the left. Even though you may have the legal right-of-way, make sure that the other driver is yielding before you proceed.