If A-text (which I assume is the only text editor you could use) doesn't let you edit more than one description at a time and you would have to search for another one, one after another, don't use it.What is the easiest way to edit attack descriptions in fire red?
I recommend using a hex editor, possibly Translhextion or GoldFinger (I use GF myself but I can't say whether it's really the best hex editor out there, others like WindHex could be better too) and a FireRed table file.
https://www.romhacking.net/forum/index.php/topic,13825.0.html
What you've gotta do is to copy the contents from that site to a notepad file, and change the extension from .txt to .tbl. After you have done this, a hex editor can open up that file and use it for "translating" bytes to the language defined with the contents of the table file.