The whole idea, in four cards
Why it matters, and when to reach for it
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It is easy to think the format of a document does not matter to an AI tool. It does, more than most people expect. A Markdown file is plain text the tool reads in full; a PDF or a spreadsheet it reads only in part. Getting the format right is often the quiet reason one task works and another quietly misses.
A Markdown file is a plain-text file (.md) that uses a few simple marks - # for headings, - for lists, ** for bold - to add structure without a heavy format like Word or PDF. Because it is plain text, Claude reads it fully and cheaply, while PDFs and spreadsheets are read only partially and cost more tokens. It is the format Claude and its skills use to store instructions and standards.
Tap any card to open it.
Pick what you are about to hand over as a source. I'll tell you if it needs converting first.