What are the desired effects of EU Sanctions how could they impact Iran?

The EU will widen sanctions against Iran following the country's weekend attack on Israel, European Council President Charles Michel told reporters in the early hours of Thursday morning after the first day of a two-day summit of EU leaders in Brussels.
"The idea is to target the companies that are needed for the drones, for the missiles," he said. The finer details are yet to be worked out, he added.
The EU will take "further restrictive measures against Iran, notably in relation to unmanned aerial vehicles (UAVs) and missiles," the European Council said in a statement.
The statement also called “on Iran and its proxies to cease all attacks" and urged all sides to exercise “utmost restraint and to refrain from any action that may increase tensions in the region.”
EU foreign policy chief Josep Borrell has tasked his staff with drawing up new measures and expanding sanctions. The EU has already targeted those responsible for making drones that Iran has sold to Russia for use in its war against Ukraine.
The idea is to expand that list to include missiles, although there is no evidence that Iran has sold missiles to Russia. Borrell said that proxy forces backed by Iran in Lebanon, Iraq and Syria could also be targeted with sanctions.