Comment by biimugan

For work, I primarily use Gemini CLI, and the one real awkward part of plan mode is that the harness can't run commands, even exploratory ones. So when I'm giving the harness a task in plan mode, it can't experiment and is either blind or relying on its training data and/or any other context (e.g. source code, documentation) I give it. And it often gets things wrong operating that way (depending on how detailed the context ends up being).

For example, the ability for the harness to call into a Python one-liner just to experiment is pretty powerful. If I'm asking it to use D2 to build an SVG graph, it can write some Python to introspect the XML to see if things appear to be placed correctly (size, x-y coords, etc.). Which is a pretty cheap way for it to experiment and verify its results before I deign to examine the rendered SVG with my own eye balls.