It would be great if there were 2 different searches:
- standard search (status quo): search in tag names only
- extended search: search in tag names + tag descriptions
That would make it easier to find some tags.
I'll give some examples for aviation.SE:
user doesn't know a certain technical term. Standard search for "drone" doesn't find anything. Searching "drone" in descriptions would find unmanned-aerial-vehicle. Same for "oxygen deprivation" instead of hypoxia.
user wants to find a health-related tag, but doesn't know which one is used for that. "Health" doesn't yield any results in the standard search. Using the tag description search, the user would find air-quality.
Also remember that for some users English is a foreign language. So the extended search is helpful for users with limited vocabulary.