How I get Claude to summarize a 90-page PDF without missing the load-bearing parts
Upload the file, ask for a structured summary plus the three claims to verify, and you skip the skim.
Long PDFs defeat a normal summary because the model quietly drops the middle. I stopped asking for 'a summary' and started asking for a job.
My prompt is: 'Summarize this in five bullet points. Then list the three claims most likely to be wrong or outdated, with the page they came from.' Forcing it to name weak spots makes it actually read the document instead of paraphrasing the intro.
For very long files I split by section and summarize each, then merge. Claude handles a single large upload well, but the section approach gives me checkpoints so I notice when a chapter got skipped.
The output is a map, not the source. I still open page 42 when the summary says something I will act on. Treat the summary as a table of contents with opinions.