Education Secretary Betsy DeVos, who made a career of promoting local control of education, has signaled a surprisingly hard-line approach to carrying out an expansive new federal education law, issuing critical feedback that has rattled state school chiefs and conservative education experts alike.

President Barack Obama signed the Every Student Succeeds Act in 2015 as the less intrusive successor to the No Child Left Behind law, which was maligned by many in both political parties as punitive and prescriptive. But in the Education Department’s feedback to states about their plans to put the new law into effect, it applied strict interpretations of statutes, required extensive detail and even deemed some state education goals lackluster.

In one case, the acting assistant secretary for elementary and secondary education, Jason Botel, wrote to the State of Delaware that its long-term goals for student achievement were not “ambitious.”

“It is mind-boggling that the department could decide that it’s going to challenge them on what’s ambitious,” said Michael J. Petrilli, the president of the conservative-leaning Thomas B. Fordham Institute, who worked in the Education Department under President George W. Bush. He called the letter “directly in opposition to the rhetoric and the promises of DeVos.”