You cannot combine tool expenses over several years. You can only claim expenses incurred during 2017 on this years tax return.
To claim 2016's tool expenses you'd have to file a adjustment request form with the CRA (assuming it would make a difference in taxes owing).
It's unclear if the $2000 was spent over the two years, or $2000 in each of the last two years.
To claim tool expenses they have to exceed $1,178 for 2017. Any amount above that threshold up to $1,678 can be claimed (ie maximum of $500). This would be entered on line 229. So if you spent $2000 on tools in 2017, you can claim $500. If you spent less than 1178 you cannot claim anything.
