Making Unity legible to coding agents
How I give coding agents enough access to inspect a Unity change, see the rendered result, and repair obvious mistakes before review.
A Unity change can compile while the visible result is still wrong. A panel may be clipped, the wrong scene may be active, or a technically correct interaction may remain unclear to the player. “The command succeeded” is not enough evidence that the task is complete.
Make the result visible
I connected coding agents to Unity through custom MCP tooling. The tools expose only the actions an agent needs for a particular job: open the relevant scene, enter play mode, move to a known state, capture the view, and run a focused check.
That changes the unit of work. Instead of asking for a code edit and hoping the interface follows, I can ask for a visible outcome and require a screenshot from the exact state where it should appear.
Use a short verification loop
A typical task follows five steps:
- State the intended player-visible result and the files or scene that may change.
- Let the agent implement the smallest viable change.
- Enter a repeatable game state and capture the result.
- Compare the screenshot with the acceptance criteria and repair obvious mismatches.
- Hand the change, evidence, and any uncertainty to a person for review.
The repository records scene ownership and verification instructions beside the code. That context has proved more useful than a longer prompt because it survives across tasks and makes mistakes easier to reproduce.
Keep judgement with the reviewer
Visual feedback catches many mechanical problems; it does not decide whether an interaction is good. A person still owns product fit, readability, feel, scope, and release risk.
The practical lesson is simple: agents improve when the environment can show them what happened. Access to a compiler is useful. Access to the rendered result, a known test state, and a clear handoff is much better.