Ask Claude this, today, with no setup:
"What did user 4421 do in our app yesterday?"
You will get an answer. It will be confident, specific, and completely made up. Claude has no access to your production database. So it does what a language model does when it has no facts: it pattern-matches what an answer should look like and hands you fiction in a calm voice.
That is the whole problem. Not that the model is dumb. That it is answering a question about your data without your data.
The Model Context Protocol fixes this, if you point it at the right source. This post is about what MCP is for a Rails dev who hasn't wired one up yet, why you'd want one over your app's activity log, and how I built the EZLogs MCP server so the answer is the boring true one instead of the confident fake one.
