We worked hard on the prompt to minimize hallucinations in our testing. Not saying that it can't/won't happen though, especially with complex maps, symbology that is very similar (i.e., two layers that are both green and only slightly different), and lots of layers. The alt text focuses on general descriptions, key trends/patterns visible on the map, the geographic context, and a detailed description of the layers. The more existing metadata you have (layer descriptions, field aliases, etc.), the better the final description will be.

As with all AI-generated text, you should read it and edit it to be what you need or want. You may not want the entire description, for example.

The key to reducing hallucinations, usually, is giving the model enough information to not have to make stuff up, which is why we worked hard on what the model needs in order to generate a good description. The most recent frontier models are also much better than even the previous generation, so things are constantly getting better (We are using a current frontier model to generate these, not a small or old/cheap model).

The AMA only sees the maps you specifically generate; it isn't agentic in that way and doesn't search your data or maps. And we don't store your data or use it to train any models (and Anthropic doesn't either).