I make LLM agents author in two formats. Here's what stopped breaking.

LLM agents will happily produce a thousand lines of plausible Markdown describing work that doesn't compile, isn't tested, and contradicts a decision the same agent wrote down two files earlier. If you want to review their output without re-reading every paragraph, some of the work product has to be machine-checkable. You also can't push everything into a schema. Intent, trade-offs, the alternative you rejected: that material dies in JSON. The interesting question is the boundary. What belongs i