Haberdashers' Abraham Darby in Madeley, Telford, was visited by inspectors on October 1 and 2.
In their report they said quality of education, behaviour and attitudes, and leadership and management all require improvement.
But it did receive good ratings for personal development, sixth-form provision and overall effectiveness at previous inspection.
The report stated: “Not all teachers routinely set work that is hard enough and challenges pupils to think deeply. Therefore, many pupils are not learning as much as they are able to.
“When work is too easy, some pupils display poor attitudes to their learning and become disengaged.
“Pupils do not achieve as well as they could in mathematics. Although the subject leader has developed the curriculum in line with the whole-school approach, there is still too much variation in the way that it is being taught."
It added: “The principal has ensured that routines and expectations for pupils’ behaviour are clear. However, there are some teachers who do not insist on these regularly enough in their classrooms.
"As a result, there are a small number of pupils whose behaviour disrupts other pupils’ learning. Leaders need to empower all staff to follow these systems so that pupils behave consistently well across the school."
It added: “Some older pupils have not learned what they needed to when they were younger. This means that they struggle in some subjects and do not achieve the GCSE grades that they are capable of.”
Principal Lee Hadley said: “Whilst it is pleasing that there are many positives identified in the report staff and governors feel it does not reveal a deep understanding of the school.
“During the inspection there was a disproportionate focus on important but small areas of the school to the detriment of the wider picture. A single agenda seemed to dominate the entire inspection and key successes were overlooked.
“The new framework is only four weeks old and this was clearly evident in the nature of the inspection.
"The processes have left committed staff feeling angry and frustrated that, amongst other things, lessons were visited for between only five and 15 minutes and that the complexity of any school is captured in a very simplistic two-and-and-half page letter.
“We will be writing to Amanda Spielman to make our concerns clear.
"Our sponsors, the governors and staff continue to believe that we are providing a rounded educational experience and that we will, as always, continue to strive to improve all areas of the school, including those identified in the report.”