Garmin is good at making invisible parts of training visible. Sleep, recovery, load, heart rate and the shape of recent sessions can all be brought into one place. The difficult part is not collecting another signal. It is connecting those signals to the decision that needs to be made today.
Imagine Monday was easy, sleep was poor, the forecast is hot and Tuesday contains the main interval session of the week. A readiness score can summarise some of that, but the score does not know why Tuesday matters. It also does not know whether Wednesday is available or whether moving the session damages the rest of the week.
Keep the plan visible
A more useful explanation would show what changed and why it may matter, then offer two sensible adjustments. The product should make the evidence easier to understand, state uncertainty and leave room for judgement rather than turning the watch into an authority.
That explanation also needs to respect the shape of the week. Moving a session is only useful when the alternative day is available, the long run still fits and the change does not simply push fatigue into another corner.
Garmin already has a strong foundation because the plan and the measurements often exist in the same system. Fewer isolated cards, clearer explanations and recommendations that preserve the purpose of the week would make the existing data much more useful.