Comment by potatolicious

> "there is a feedback loop like this: LLM <--> deterministic agent?"

More or less, though the agent doesn't have to be deterministic. There's a sliding scale of how much determinism you want in the "overseer" part of the system. This is a huge area of active development with not a lot of settled stances.

There's a lot of work being put into making the overseer/agent a LLM also. The neat thing is that it doesn't have to be the same LLM, it can be something fine-tuned to specifically oversee this task. For example, "After code generation and build/test has finished, send the output to CodeReviewerBot. Incorporate its feedback into the next round of code generation." - where CodeReviewerBot is a different probabilistic model trained for the task.

You could even put a human in as part of the agent: "do this stuff, then upload it for review, and continue only after the review has been approved" is a totally reasonable system where (part of) the agent is literal people.

> "And there's a asymmetry in strictness, i.e. LLM --> agent funnels probabilistic output into 1+ structured fields, whereas agent --> LLM can be more freeform (stderr plaintext). Is that right?"

Yes, though some flexibility exists here. If LLM --> deterministic agent, then you'd want to squeeze the output into structured fields. But if the agent is itself probabilistic/a LLM, then you can also just dump unstructured data at it.

It's kind of the wild west right now in this whole area. There's not a lot of common wisdom besides "it works better if I do it this way".

> "1) how does the LLM know where to put output tokens given more than one structured field options?"

Prompt engineering and a bit of praying. The trick is that there are methods for ensuring the LLM doesn't hallucinate things that break the schema (fields that don't exist for example), but output quality within the schema is highly variable!

For example, you can force the LLM to output a schema that references a previous commit ID... but it might hallucinate a non-existent ID. You can make it output a list of desired code reviewers, and it'll respect the format... but hallucinate non-existent reviewers.

Smart prompt engineering can reduce the chances of this kind of undesired behavior, but given that it's a giant ball of probabilities, performance is never truly guaranteed. Remember also that this is a language model - so it's sensitive to the schema itself. Obtuse naming within the schema itself will negatively impact reliability.

This is actually part of the role of the agent. "This code reviewer doesn't exist. Try again. The valid reviewers are: ..." is a big part of why these systems work at all.

> "2) Is this loop effective for projects from scratch? How good is it at proper design (understanding tradeoffs in algorithms, etc)?"

This is where the quality of the initial prompt and the structure of the agent comes into play. I don't have a great answer for here besides that making these agents better at decomposing higher-level tasks (including understanding tradeoffs) is a lot of what's at the bleeding edge.