Have you any example materials that show a harness that an agent can be pointed at an app with some sort of telemetry tool, the results it gained and the cost of doing so? Because my experience is the same as the parents - the LLM goes on massive tangents, and the more tangents it goes on the worse the results get.
Ultimately the harness is me and the experience is like managing an unruly toddler. You have to pay attention to what it does and issue corrections. Skills and prompts and AGENTS.md do some, nested sets of agents do some, but over it all is me keeping track of what it's doing and needs to do.
You have to size the unit of work to its useful attention span, you have to have code architecture that is conducive to units of work, and you have to have tools like ticket managers, etc. that keep the big picture and smaller pictures in mind. Reverting from agile practices to more pre-planning whole project documentation and architecture decisions helps.
But in the end it's you. LLMs have their limits and need humans to direct them.