Currently there is no way to get specific information about failed webcheck. If we trigger like this:

{{HOST.HOST}:web.test.fail[Web checks].last()}<>0 and {{HOST.HOST}:web.test.error[Web checks].strlen()}>0

We can only get some generic information about number of step which is failed from {ITEM.VALUE1} and short description about which check is failed from {ITEM.VALUE2}, eg:

required pattern "$Pattern" was not found on $URL

or

response code "200" did not match any of the required status codes "451"

I cannot get precise information about name of step which is failed or URL used in step if error was tied to response code check.