Charting intent refers to your goals and aims when charting. It's an important aspect to consider as a chart without intent can end up being very confusing to play. Charting intent is a very simple concept, as it only really refers to what you as the charter want to do with the chart, and while there's other aspects to it, its really as simple as thinking to yourself "I want to make x type of chart to this song" and then sticking to that.
It's important because without intent, the chart you make could end up aimless, and the last thing you want to do is make a boring chart. Charting intent makes sure that your chart has value no matter what, as it lets you limit yourself. For example, if you wish to make a jumpstream chart, you'll be using a lot of jumpstream patterns, and will want to avoid any patterns that are perticularly nasty. Below is an example of what people would expect and enjoy in a jumpstream chart vs. what would make a lot of people quit out of a jumpstream chart.
Not to say the second pattern is bad, it's actually one of my favourites, but it doesn't belong in a scoring chart focused on jumpstream
Intent is what gives your charts identity. It's what makes people want to play your charts over other peoples, and what lets you limit yourself to make your chart more unique. You need to decide yourself what you want to do with your chart, however there is no limit as to what that could be. You have complete freedom, there's nothing wrong with mixing up things, if its your intent. For example, if you did the things above, but intentionally mixed jacks and JS, people might play it because you'll have made it consistent and enjoyable, appose to people feeling like the jacks don't belong whatsoever. Obviously this can also go for other things as well, I'm just using these as an example. Dumps often use accurate segments to emphasise sounds, and some accurate charts may dump wubs in electronic music for emphasis, by limiting yourself, you give yourself more creativity in how you can approach things. If you have clear intent in mind, then you'll also be able to hone the skills for that specific intent. For me, this was mineart/jack charting. I put jacks in all of my charts because I love charting jacks, and have learned over the years how to incorporate jacks into any chart I make.