The calculation for trades tool allowance also includes the Canada employment amount, so the cost of the tools has to be greater than $1,146.
Per CRA:
Maximum deduction for eligible tools is the lesser of:
a) $500; and
b) the amount, if any, determined by the formula
A − $1,146 where
A = the lesser of:
1. the total cost of eligible tools that you bought in 2015; and
2. your income from employment as a tradesperson for the year
plus the amount you received in 2015 under the Apprenticeship Incentive Grant and the Apprenticeship Completion Grant programs;
minus the amount of any Apprenticeship Incentive Grant and Apprenticeship Completion Grant overpayments that you had to repay in 2015.
