In this spot we consider to call for a set value with pocket 5s. But first of all lets consider our position and players left behind: How likely is a squeeze, call etc?; . Generally we are allowed to call middle pairs for set value up to 3bb, maybe 4 considering other effective stack sizes.
Also we need to think about made actions by the original raiser. Seems like he is going for isolation raise of the limper with a tight range (if no stats provided). Check his 3bet stat. We are not worried about the limper though.
Moreover we need to calculate our SPR (stack-to-pot-ratio). Lets do that (assuming we have called the raise):
MP Limper 250 + HJ raise 1250 + Hero CO call 1250 + limper will call another 1000 + blinds 375= 4 125 pot. Hero stack 13000/4125 = 3.1 SPR - which is very low. with this SPR we are playing all in poker on flop.
As a conclusion I think that we wont have enough equity to be +ev in long run against 2 villains in this exact situation.

We need to think about made actions by the original raiser. Seems like he is going for isolation raise of the limper with a tight vidmate range (if no stats provided). Check his 3bet stat. We are not worried about the limper though.