This is the 4620th most frequent Polish word.
mieści
"Fits" or "is located."
Here, 'mieści' refers to containing or housing something within a location.
To miasteczko mieści wiele zabytków.
This town houses many historical monuments.
In this sentence, 'mieści' is used to express the capacity of a location or space to hold something.
Sala konferencyjna mieści pięćdziesiąt osób.
The conference room accommodates fifty people.
Here, 'mieści się' implies that the box is capable of containing the tools within its volume.