If this is the first year that you have claimed these tools, you have just been introduced to the "half year rule"  You only get 50% of the CCA the first year.

My other concern is that class 12 is not commonly used for small tools. If any individual tool cost more than $500 it should be in class 8.  Generally speaking, tools that cost less than $200 are not depreciated at all.  If you have a bunch of small tools, it becomes difficult to adjust the depreciation when tools wear out and are written off.