Broken by bread, ultimately toaster fails special checks (4,5)

'special checks' is the definition.
The answer and definition can be both related to thinking as well as being plural nouns.
Perhaps there's an association between them I don't understand?

'broken by bread ultimately toaster fails' is the wordplay.
'broken by' indicates anagramming the letters (a broken form of the letters).
'ultimately' suggests the final letters.
'fails' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
The final letter of 'bread' is 'd'.
'd'+'toaster'='dtoaster'
'dtoaster' with letters rearranged gives 'roadtest'.
'roadtest'+'s'='ROAD TESTS'

Can you help me to learn more?