This ability grants a chance to endure what would otherwise be a stunning blow, from any angle, without being stunned.
Further ranks improve the chance.
Yther Ore.
Okay, that's great, does it give a percentage or just the vague improve the chance? Any numbers or at least anecdotal evidence? If it just has the vague even that would be good to be edited in the main description. Possibly enabling comments? If it describes a percentage chance or some other numerical equivalent that would be a vast improvement over the current info. Anyway you could get it updated?
If you are talking about the in-game description, better to /feedback it or post on the official SOE site https://forums.station.sony.com/eq/index.php where a developer should see it. They don't come here to read stuff in general.
If you're talking about the wiki page, I generally add in a notes column (you can add upto two at the moment), with that info if it's available. I haven't really looked for it for this one, but there may be parses somewhere that indicate how much it is. If you come across some, just point me to it, and I'll edit it in, if you're not into doing the wiki stuff. If you are, then https://everquest.allakhazam.com/wiki/Template:EQ_AA_Table explains the formatting of the table and https://everquest.allakhazam.com/wiki/Template:EQ_AA explains the AA header and description formatting. https://everquest.allakhazam.com/wiki/EQ:Lay_On_Hands is an example with two notes columns.
Also, from the way other AAs work, I'd assume the first 3 ranks are probably around a 10-25% total chance, then lower chance for further ranks, probably 1-5% each rank. Again, though, I don't know for sure. That's just how most of them work. See http://everquest.allakhzam.com/wiki/EQ:Combat_Agility for an example with percentages. It's much lower, but also has tons of ranks.