Why you hand Claude the spreadsheet, not a description of it

Here’s the failure mode almost every founder hits at least once: you ask Claude to draft an investor update, and to save time you describe your metrics in a sentence — “revenue’s up a bit, churn is stable, we hired one person.” The draft that comes back is vague, hedged, and generic. The instinct is to blame the model. The actual problem is the input: you handed it a summary and got a summary back.

The fix is mechanical, not clever: paste the actual spreadsheet, the actual export, the actual thread — not your description of it. Claude can only work with what’s in front of it, and a real number (“MRR moved from $18,400 to $21,100”) produces a specific, confident sentence in a way that “revenue’s up a bit” never will.

This generalizes past investor updates. Any time output feels thin or generic, check what you actually gave it first, before you conclude the tool can’t do the job. Nine times out of ten, the fix is handing over the real artifact, not rewriting the prompt.

See the investor-update playbook for the full prompt this builds on.