"potent tool" is correct and can be used in written English.
You can use it when referring to something that has the power (potential) to be effective and efficient. For example, "Data analytics has become a potent tool for making informed business decisions."
Nature photography has become a potent tool in this struggle.
In any case, words may not be the playwright's most potent tool here.
"They have discovered that this is an incredibly potent tool for selling".
Several ministers said the continued resistance of the Palestinians to occupation was a more potent tool than any statement or plan devised by Arab summit meetings.
As development practitioners, we find music to be a very potent tool to mobilise communities for communal work and participate in development.
But they also hinted that formal statements, once a potent tool for managing currency markets but now more general in nature, would soon end.
Cruz added that the military commanders he has consulted insist that "the most potent tool to use against ISIS is overwhelming airpower".
"This is a potent tool given to Congress by the Constitution explicitly to act as a check on executive power," Cruz wrote in a column for Politico.
This could be a potent tool for a newsroom (we are building one at Les Echos that will primarily benefit our news team).
"We continue to see the Urban Transit Hub Tax Credit as an enormously potent tool, even during economic uncertainty," said Stefan Pryor, Newark's deputy mayor for economic development.
The federal whistle-blower law, known as the False Claims Act, has been a potent tool for keeping government contractors honest since it was last amended in 1986.
