The anatomy of copy that works
Every ad has three main jobs to do, and most weak ads only manage one of them.
It has to match the search. If someone searches "emergency boiler repair," your headline needs to speak to that exact need, not a general line about your plumbing company. The closer the match, the more likely someone is to click, and the better your Quality Score.
It has to be specific. Vague claims like "quality service" or "trusted by many" don't tell anyone anything. Specific claims like "same day callout" or "fixed price, no hidden costs" give someone a real reason to choose you over the next result.
It has to set expectations for the click. The person clicking should have a rough idea of what they're about to see. If your ad promises a free quote and the landing page asks for a credit card, you've broken that expectation, and they'll leave.
Get those three things right and your ad copy stops being decoration and starts doing actual work.
Write descriptions that address the real concern
Headlines get people to look. Descriptions get people to trust you enough to click. That means your description lines shouldn't just repeat the headline in different words, they should handle the objection that's stopping someone from clicking in the first place.
Think about what's actually holding your prospect back. If you're a tradesperson, it's often price and trust: will this cost more than expected, and is this company reliable? If you're B2B, it might be risk: will this actually work for a business like mine?
Write your description lines to answer that directly. Instead of "We offer great customer service," try "No call out charge, fixed price agreed before we start." Instead of "Trusted by businesses across the UK," try "Used by over 200 UK manufacturers since 2019."
The specific version always beats the vague version, because it gives someone a concrete reason to believe you, instead of asking them to take your word for it.
Quick check: Read your current description lines back. If you could swap them onto a competitor's ad without changing a word, they're too generic to be doing any real work.
Use copy to pre-qualify clicks
Here's something a lot of advertisers get backwards. More clicks isn't always the goal. The goal is more of the right clicks, from people who are likely to actually convert once they land.
Your ad copy can do some of that filtering for you before someone even clicks. If your service starts at a certain price point, say so. If you only work with businesses over a certain size, mention it. If you only cover a specific area, put the location in the copy.
This might feel counterintuitive, since it will reduce your overall click volume. But it also means the people who do click are far more likely to be a genuine fit, which improves your conversion rate and lowers your cost per lead. A smaller number of qualified clicks almost always beats a larger number of clicks that were never going to convert anyway.
Responsive search ads and testing
Most Google Ads accounts now run on responsive search ads, where you provide multiple headlines and descriptions and Google mixes and matches them to find the best combinations. This is useful, but it only works well if you give it good material to work with.
A few things matter here. First, don't just write ten versions of the same headline. Give Google genuinely different angles to test: one focused on speed, one on price, one on trust, one on a specific feature. That variety is what lets the system actually learn something useful.
Second, check the "Ad strength" indicator, but don't treat it as gospel. It rewards variety and use of the available fields more than it rewards good writing. A "poor" rated ad with sharp, specific copy will often outperform an "excellent" rated ad full of generic filler.
Third, look at the asset performance report regularly. Google will show you which headlines and descriptions are pulling their weight and which ones are barely being shown. Replace the weak performers rather than leaving them in indefinitely. Ad copy isn't something you write once and forget, it's something you keep refining as the data comes in.
The bottom line
Ad copy that converts is specific, matched to the search, honest about what someone is about to click into, and written to attract the right person rather than the most people. Combine that with genuine variety in your responsive search ads and a habit of checking what's actually performing, and your copy starts doing real work instead of just filling space.
If your click through rate looks fine but your conversions don't, this is usually the first place to look.