There’s no sugarcoating it. Just three years after they were introduced as the silver bullet that would save public education in Pennsylvania, the Keystone exams have failed.

The exams were supposed to become a graduation requirement for students starting with the class of 2017. But lawmakers and Gov. Tom Wolf have pushed that back to 2019 and instructed the state Department of Education to replace the requirement with something else.

The reason is obvious: in 2015 barely half of Pennsylvania students achieved the “proficient” score in three Keystone Exams — Algebra I, Biology and Literature — that would be required to graduate from high school, according to an August report from the department.

In their desire to walk back pronouncements of the exam’s panacean qualities just a few years ago, department officials suddenly found themselves hawking a much different worldview on student success.

“(P)assing high school exit exams is not the sole valid measure of mastery ... nor is it the sole reliable indicator of readiness for postsecondary success,” the department said in its report. “Postsecondary success looks different for different students.”

You don’t say? That’s not what officials were preaching in 2012, while in the process of cramming more standardized testing into school districts’ already-packed schedules.

Keystone exams will “guarantee that a Pennsylvania diploma reflects the skills and knowledge graduating students need to be successful in college and the workplace,” state officials said.

Yeah. Except when the requirements ignore the needs of career and technical students, fail to account for special needs students entirely, impose ridiculous remedial requirements for those who fail, and offer, as an alternative, a phony “project-based” assessment that even the department now admits is an “ineffective and inefficient strategy,” to demonstrate student achievement.

But while they may not be effective at determining how much students have achieved, the tests are still a perfectly adequate tool for state officials to use when evaluating the people teaching them. Keystone exams will remain a cornerstone of the state School Performance Profile scores, which in 2013 replaced AYP as Pennsylvania’s main school accountability system under the federal No Child Left Behind Act.

It’s yet another chapter in Pennsylvania’s quixotic quest for one-size-fits-all accountability standards. State officials have again poured millions of dollars and wasted years of effort into developing yet another point-in-time academic assessment tool, as if students didn’t already have enough of those — hello PSSA, PASA, NOCTI, NIMS, ASVAB.

Of course, given how the school accountability system is set up these days, the Keystones are far better at casting aspersions on the work of teachers and school administrators than determining whether students deserve a high school diploma.

With state officials engaged in a rousing game of ideological hot-potato over the tests, it’s fair to wonder whether that wasn’t actually the goal in the first place.