Running pt-table-checksum on a table in different databases
I don't see anything along those lines in the Percona Toolkit Documentation.

There is something you can do to cheat

Scenario


datadir is /var/lib/mysql
Master has test database
Slave has test_slave database


You could create a symbolic link in one of two ways

TECHNIQUE #1

On the Master, run

ln -s /var/lib/mysql/test /var/lib/mysql/test_slave
chown mysql:mysql /var/lib/mysql/test_slave


TECHNIQUE #2

On the Slave (if there is no test database), run

ln -s /var/lib/mysql/test_slave /var/lib/mysql/test
chown mysql:mysql /var/lib/mysql/test


NEXT STEP

Once you created the symbolic link, you can run the checksum against test

pt-table-checksum --host=localhost --databases=test --max-load=Threads_connected:25 --no-check-replication-filters


or against test_slave

pt-table-checksum --host=localhost --databases=test_slave --max-load=Threads_connected:25 --no-check-replication-filters


EPILOGUE

When done, you can remove the symbolic link.

Give it a Try !!!