You can't. What appears in description for search is up to Google, Google *may* choose to use the meta description if one is given but phpBB doesn't have them. They may choose to ignore the description if you had one and provide their own. Note that meta descriptions should be unique for each page so you can't just simply add one in overall_header.html for every page. When no meta description is present Google will choose something on the page. There was extension for this but the one i found appears out of date.
Presumably your screenshot is from footer, you may want to double check that the bots group permissions are correctly set so they have access to the page.
You can add this to overall_header.html anywhere between the <head> tags but it only applies to index page.
Code: Select all
<!-- IF S_INDEX --><meta name="description" content="{SITE_DESCRIPTION}<!-- ENDIF -->
Adding a description to viewforum and viewtopic gets complicated because once again you want it to be unique.
“Results! Why, man, I have gotten a lot of results! I have found several thousand things that won’t work.”
Attributed - Thomas Edison