Palestinian rockets are a violation. Israeli missiles are a violation. But the ceasefire agreement describes the dispute-resolution mechanism i.e. the side that is aggrieved doesn't take matters into their own hands; they take their complaint to the Egyptians. Israel didn't, ergo, Ya'alon can not claim that Israel's response was "in line with the ceasefire agreement".
Zionist Union announces support for so-called anti-terrorism bill (Haaretz)