Objective key results, or short OKR, is a concept that is easy to understand but hard to master: You set an objective, such as "Increase user base", and define three key results, such as "Boost logins from 1% to 1,4%" or "Increase form submissions on the homepage by 10%". The 10% increase has to be something that you personally or your team can achieve. You want to rule out external reasons, such as seasonal factors or growth over the years or a special influencer such as Covid-19.
We can come up with several (hypothetical) reasons that could justify a "No, probably that was not a good key result!": So the "10% more" key result is not specific enough as it does not define something that can be easily attributed to you.