Writing a decision down isn't enough.
People can still spend days solving a problem others had already worked through, even with a perfectly good decision record. They need to know where it's been recorded before they can read it. If it's buried somewhere in some meeting notes or, even worse, some Slack thread, they'll have a hard time tracking it down. Most likely, it'll be information that's as good as lost.
Decision records must live in one central place that's easy to find for anyone on the team. Yes, you could link to it from your design system, any existing implementation, even code or Slack notes. You don't have to copy it everywhere or keep several versions updated. You only need routes to it from the places people already use.
The decision record needs a useful name too. "Chart summaries and access to individual entries" tells people more than "Team meeting, March 12." At the same time, I said in a previous email, each decision record should have a stable identifier. Something like a unique ID, if you will. Why? Decision record titles may change and that's no reason why their IDs should as well. If you're going to keep creating these decisions, eventually, you'll notice they start to relate to each other. Having IDs will make this correlation much easier than a long title.
Not every feature needs a decision record. Some will, so better make this part of finishing the work. Part of the definition of done. Leave a record of your reasoning somewhere the next people can find it and benefit from your lessons.
For our chart example, the decision record could live in a "Design decisions" section of the design system. The chart component links to it. So does the JIRA ticket and the code commit. When the sleep team starts exploring charts, any of these routes leads them to the reasoning before they repeat the work.
That should be the test before calling the decision record finished.
Ask someone outside the team where they'd look for guidance on building a chart. Let them follow that path without telling them what to search for. If they can't find the decision, adding another document won't help. Instead, put a link to it exactly where they looked.