Meta Descriptions and URL Slugs for AI-Generated Guides: What a Tool Gets Right and the Two Things to Check
A writing tool produces a title, a slug and a meta description for every guide, and most sites publish all three without looking. Two of them are easy to get right and the tool usually does. The third, the description, is the part of the page most likely to be the title again in different words, which is two lines of the result wasted on something the reader just read.
This post covers what each of the three is for, the formula for a buyer guide's description and why generated ones default to restating the title, the slug rules and the one about never changing it, what Google does with descriptions (rewrites most of them), and the two checks to run before a batch goes out.
The titles post covers the title itself; this is the other two fields next to it.
The short answer
The description is for the click, not the ranking: about 150 characters, front-loaded, saying what the title didn't (the verdict, the count, the price band, who it's for).
The slug is for the address: the keyword in three to five words, lowercase, hyphens, no year, no stop words, and never changed after publishing. Before a batch: read every description against its title and reject any that restate it; read every slug for a year or a stop word.
What each field is for
| Field | Where it shows | Its job | What a tool defaults to |
|---|---|---|---|
| Title | The blue link in the result, the tab, the share card | Match the query, earn the click | Usually fine; the titles post covers the patterns |
| Meta description | The two lines under the title, when Google keeps it | Say what the title didn't; turn the impression into a visit | The title again, longer |
| URL slug | The address; the green line in the result; every link to the page | Say what the page is, permanently | The full title, with stop words and sometimes a year |
The description formula
A buyer guide's title already says the category and the reader ("Best Bike Lights for Commuting"). The description's job is the next thing a searcher wants to know: what's in it and what it concluded.
Four ingredients, in roughly this order, in about 150 characters: the count ("Ten lights"), the basis ("compared on beam shape, mount and run time"), the verdict ("the Metro Pro for lit streets"), and the price band or the second pick ("under $70"). Front-load, because phones cut at around 150 and Google sometimes cuts earlier.
Example: "Ten commuter lights compared on beam shape, mount and run time. The Metro Pro wins for lit streets; the Lezyne for riders who swap bikes. All under $70." That's 151 characters and none of it is the title.
For an informational post, the formula is the answer: the first sentence of the snippet-format paragraph, trimmed. For a comparison, the verdict and the deciding difference.
Why generated descriptions restate the title
A tool asked for a description with only the title and keyword as input has nothing else to say, so it says the title. Given the verdict, the count and the price band (which it has, because it just wrote the guide), it writes the formula above.
If your tool's descriptions all start "A guide to" or "Discover the best", the fix is in the inputs, not the edit; the editing post covers the pass, and the description is a ten-second check in it.
The slug rules
- The keyword, not the title. /best-bike-lights-commuting/, not /the-10-best-bike-lights-for-commuting-in-2026-tested-and-ranked/.
- Three to five words. Enough to say what the page is, short enough to read in the result.
- No year. The year dates the URL the day the year changes and you can't update it without a redirect. Years go in the title, where they can be edited.
- No stop words. Drop "the", "for", "a", "in" unless removing one changes the meaning ("lights-for-commuting" reads fine as "lights-commuting"; "vs" stays).
- Lowercase, hyphens, no underscores, no trailing numbers from a tool's duplicate check ("-2" means two pages collided; fix the collision, not the slug).
- Never change it after publishing. It's the page's identity in the index, in links and in Search Console. If you must, 301 the old one and expect a few weeks of wobble.
The domain post covers the part of the URL before the slug; the same "decide once, then leave it" rule applies.
What Google does with descriptions
Google rewrites most meta descriptions, picking a passage from the page when it matches the query better than what you wrote. That's not a reason to skip them: for the main query the page targets, your description usually survives, and it's the one that gets most of the impressions.
For long-tail queries Google will often pull a sentence from the FAQ or a product section, which is a reason to make sure those sentences are complete on their own.
What Google never does is rank a page on its description. Keyword-stuffing it changes nothing except the click-through rate, downward.
The two checks before a batch
- Description against title. Read them side by side for every guide. If the description could be deleted without losing a fact the title didn't carry, rewrite it with the verdict and the count. Thirty seconds each.
- Slug for a year, a stop word or a "-2". Scan the list of slugs as a column. Anything with a four-digit number, "the", "for", "a" or a trailing number gets fixed before publishing, because after publishing it's permanent.
Doing it with AffSERP
AffSERP's X Best Review tool writes the meta description from the guide it just wrote (the count, the basis, the verdict, the price band) rather than from the title, and builds the slug from the keyword: lowercase, hyphenated, no year, no stop words.
Both are shown in the editor before publishing, which is where the two checks above take their thirty seconds. Slugs are left alone on Refresh, so a regenerated guide keeps its address.
FAQ
Do meta descriptions affect SEO?
Not rankings; Google has said so for years. They affect the click: the description is the two lines under the title in the result, and a good one turns an impression into a visit. Google rewrites about two-thirds of them when it thinks a passage from the page fits the query better, so write it for the main query and accept that long-tail queries get a rewrite.
How long should a meta description be for a blog post?
About 150 characters, which is what shows on a phone before truncation; desktop shows up to around 160. Front-load it: the useful half in the first 100 characters, because that's what survives both cuts. Shorter is fine if it says the thing; padding to 160 helps nothing.
Can AI write meta descriptions?
Yes, and the default output has one failure: it restates the title. 'A guide to the best bike lights for commuting' under a title that says 'Best Bike Lights for Commuting' wastes the two lines. Give the tool the verdict and the count and it writes 'Ten lights tested on paper and in owner reviews; the Metro Pro wins for lit streets, the Lezyne for riders who swap bikes. Under $70 either way.' That earns the click.
Should I change a URL slug after publishing?
No, unless you set a redirect and have a strong reason. The slug is the page's address in Google's index, in every link pointing at it and in Search Console's history; changing it resets all three. Get the slug right before publishing (short, the keyword, no year, no stop words) and then treat it as permanent.
AffSERP writes the meta description from the guide it just wrote and the slug from the keyword, with no year and no stop words, both shown before you publish.
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