What I found. I auto-generated architecture diagrams for this site’s ten project pages, shipped them, and deleted them the same day. My sample, my judgment — but the reason generalizes enough to share.
Eight of the ten architectures were already linear pipelines before any rendering decision: scraper → validator → database → app. Drawn as boxes and arrows, those strips told a reader nothing the one-line description didn’t — they just took ten times the space saying it.
The keep/kill question I ended with: does the flow branch, gate, or loop? A human approval gate, parallel inputs converging, a feedback loop — that’s shape, and shape is what prose carries badly. Two of ten had it; they got real, hand-drawn diagrams with annotations. The rest got their sentence back.
Corollary I didn’t expect: auto-generation pushes you toward formats simple enough to render — which selects for exactly the diagrams not worth drawing.