I hope to correctly understand your problem :executing a script after mysql restart.
So, my first solution is below :
From the manual :
IF CHANGED [MD5|SHA1] CHECKSUM [[<X>] <Y> CYCLES]
IF CHANGED TIMESTAMP [[<X>] <Y> CYCLES] THEN action
I think you can adapted this as follow :
check file mysqlpidfile path <path of pidfile>
if changed sha1 checksum
then exec "mysqlreload.sh"
Add a simple :
check process mysql with pidfile mysqlpidfile
start = "..."
stop = "..."
And I think you have it.
(when mysql restart, it will have a new pid, so a different checksum or timestamp
I'm not sure of the syntax (can't test), but I think it will work.