I recently needed to recommend some IAM permissions for an assistant on a hobby project; not complete access but just enough to do what was required. Was rusty with the console and didn't have direct access to it at the time, but figured it was a solid use case for LLMs since AWS is so ubiquitous and well-documented. I actually queried 4o, 3.7 Sonnet, and Gemini 2.5 for recommendations, stripped the list of duplicates, then passed the result to Gemini to vet and format as JSON. The result was perfectly formatted... and still contained a bunch of non-existent permissions. My first time being burned by a hallucination IRL, but just goes to show that even the latest models working in concert on a very well-defined problem space can screw up.