Massachusetts fixed blade carry?

[Daniel Moore]

If I carry a fixed blade with a 5" blade, single edged, in a kydex teklock sheath off of my belt with a little bit of the bottom of the sheath showing from under my shirt and use it responsibly, is that legal (excluding local municipal laws)? I've never found a blade length limit except for in Boston and on dirk knives, daggers, stilettos etc. If the sheath is mostly covered by my shirt, is that considered concealed even though it's on my belt?

Thanks!