Do not copy text verbatim from Wikipedia or elsewhere into tag wikis and excerpts. Not even if you do so in a license-compliant way. Here is why:
- Any idiot can type the name of an anime or whatever into Google or Wikipedia and find exactly the same thing.
- See #1.
If you are in the suggested edits queue, you should know that there is a special rejection reason exclusively for edits to tag wikis:
This edit copies a significant amount of content from an external source. Generic descriptions such as encyclopedia articles and ad copy do not provide useful guidance; try creating something useful to this community specifically, and be sure to attribute the original author. See: How to reference material written by others.
Please use this rejection reason liberally. Here's a protip to get you started: if you see Japanese characters, there's a 99% chance it's copied from Wikipedia. Frankly, if you see anybody editing a tag wiki (not an excerpt; an actual wiki body) at all, it behooves you to google the first sentence and see if it shows up on Wikipedia or MAL. Odds are, it will.
(What prompted this? Well, someone just went through and made a buttload of bad suggested edits to various tag wikis, and most of them got approved.)