What
The Read tool is how Claude opens files. Its description includes a sentence saying it can read PDF files. Whether that sentence is shown now depends on a check that looks at something about the current request, instead of a fixed one.
Why
PDF support may now be described differently depending on the model or situation. The Read tool description captured under this release is unchanged from the previous release across the models checked.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
It is unclear what the new check looks at to decide whether the PDF sentence is shown.