The description tells you what a seller wants you to think. The changelog tells you what they have actually been doing. It is the most honest part of an item page.
Look at the dates first
Not the number of entries, the spacing. An item updated three times in the last six months is alive. One with twenty entries that all stop eighteen months ago is not, however impressive the list looks.
Look for compatibility work
Entries like "PHP 8.3 support" or "tested against MySQL 8" tell you the seller is keeping up with the platforms you are going to run this on. Their absence over a long period is a warning, because eventually your host will move and the script will not.
Read what the fixes are about
A steady run of small fixes is healthy: people are using it and the seller is responding. A long gap followed by a burst of critical fixes suggests the seller only returns when something has gone badly wrong.
Watch for silent rewrites
A jump from 1.9 to 3.0 with a one-line note is worth a question before you buy. Ask the seller what changed and whether your customisations would survive it. If they cannot answer clearly, that is your answer.
No changelog at all
It is not automatically bad on a new item, but on one that has been listed a year it means either nothing has changed or nobody is writing it down. Neither is what you want underneath something you are about to depend on.
Related: how to check a script before you buy it.
