It seems like you have excellent intentions....

How about this....

put up a little pegboard.
Have the names or street numbers of the neighbors.
When they borrow something put the item on a 3x5 card so that they know
you consider the tools to be valuable.

THEN - If a tool gets lost - like the current situation, you just go
and buy a replacement at full price for that tool and put the receipt
up with the name of the borrower.

THEN if they come back to borrow something else, you go to their name
and - the bill will be there - if they pay the full price then they can
borrow again...

In the past there have been computer simulations of various stratgies
for "getting along".
I seem to remember two strategies doing well-
1) TIT for TAT (which is what I described above)
and
2) TIT for TWO TATs - which did slightly better in the simulations (you
give the person a second chance...)


I think you need to establish that YOU value your tools -

good luck and report back!
Phil