In plain English
Frame rate is how many images a game draws each second; capping it saves battery. A per-game profile is a set of settings that loads when that game starts. An agent here is an AI assistant that can run commands on a computer.
When it comes to gaming, I have little time to do it. I just want to sit down and play without having to tweak performance settings all the time. So on Sunday I asked Claude Code to set up per-game profiles on my Lenovo Legion Go over my home network, then to "do the frame rate caps too". It picked 60 frames a second for the 112 lighter games and wrote the cap into Steam's per-game settings. Reading Steam's config file back showed the new value saved for all 112.
Then I asked it for screenshots for a guide. The first one, of Steam's Performance panel with Celeste running, showed "Frame Limit 144 FPS".
Steam had accepted the setting and stored it. The Frame Limit slider reads a different setting, gamescope_app_target_framerate. Steam also treats the Legion Go's built-in screen as an external display, so the value the agent had left uncapped for a TV applied in handheld too. The agent wrote the setting the slider uses, closed and relaunched FEZ, and took another screenshot. It showed 60.
I probably would have noticed when actually playing. This is a games machine, and there is no critical data on here.
On a first run, I don't accept "done" from an AI tool without checking. Anything new or recently adjusted needs oversight. Here, that meant asking for a screenshot of the panel the setting is meant to change, taken with a game running.
The full walkthrough, with every prompt and the screenshots, is in the guide: Per-game profiles on a SteamOS handheld, set up by an AI agent.