The Scottish Parent Teacher Council (SPTC) said the reports often seemed to be written to a template with little personal information about the school.
However, schools quango Education Scotland, which includes the schools inspectorate, said officials had been working with parent representatives to improve the reports. The body has also made the reports more concise in recent years in an attempt to make them more accessible.
Inspectors will also interview some of the parents and a cross-section of the parent body will be issued with a questionnaire.
The issue is important because inspection reports are one of the most important ways families can find out what their local schools, and others in both the state and private sector, are like. Many parents look at league tables of exam results to assess the quality of schools, but these can be meaningless unless wider information about the school's catchment area and particular strengths or weaknesses are taken into consideration.
Eileen Prior, executive director of the SPTC, called for a revamp of inspection reports to make them more relevant. "As things stand there are challenges with the information that's coming to parents from inspection," she said.
"Parents tell us they barely recognise their school from the inspection report letters that they get now.
"There is still a concern that these are a bit of a cut-and-paste job and that the letters are not adequately reflecting the individual schools. The language can also be impenetrable and vague."
The National Parent Forum of Scotland said it had been working with Education Scotland to improve the input from parents.
Iain Ellis, chairman of the forum, said: "We have been working with members of the inspection teams to ensure parents are involved as much as possible.
"Things are improving and the parent council also gets access to a far more detailed report which puts some meat on the bone.
"Generally, we want the inspection teams to ask more direct questions of parents to ensure their view is fully represented."
An Education Scotland spokeswoman said the feedback from parents who received inspection letters was usually positive.
She said: "Almost all of them find the report covers all matters of importance to them. They also find them helpful in understanding any strengths and weaknesses the school may have.
"In response to feedback from parents in 2010/11, we changed the format of inspection reports and started reporting directly to parents via letter in September 2011.
"In this way, we aim to present our findings clearly and concisely. The letter to parents aims to reflect the school's work and provide clear evaluations.
"At all times we aim to ensure that all those associated with the school understand inspection processes and outcomes and we always make ourselves available to work with them to achieve this."
Statistics from September 2011 to August 2013 show 93% of parents found reports "clear and easy to read" while 98% said the reports covered "all matters of importance".