Read up on 'help stats' and 'help skills'. In those help files we provide you with very vague means of gauging your abilities based on this table:
SCORE --- ABILITY
U T S R --- Bad
Q P O N --- Below Average
M L K J --- Above Average
I H G F --- Good
E D C B A --- Really Good
You need to remember that most everything you do in the game should draw on a skill and one or more stats. Generally speaking your results should be closer to the LOWER of the two.
Example. I have P level INT and D level Artistry and I want to write a song. It's probably gonna be below average. Average on a good day. It won't be good or really good.
Example. I have C level charisma and O level Artistry. When I perform it will likely be Above Average but not Good or Really good.
Example: I have R level INT and K level Artistry and write a poem. It should be Bad or Below average. Nothing Above average, Good or Really Good.
Example: I have C level CHA and NO Artistry. My performance should be Below Average at best. Probably Bad just as often.
It's not a perfect science but if you pick the attribute and skill that makes the most sense and use the lower or slightly above the lower if the other is much better, you should have a good handle on what your end product should look like
Aside from staff YOU are the only one who knows your stats and skills so it is on YOU to try and ensure the performance or creation reflects your stats and skills. That is why I wrote this up to help you gauge what your results should kind of look like. Sometimes this means you have to intentionally mess up or dumb it down or help guide the crowd if they are making you out to be better than you are.
As a rule, once you are in the average band or above in INT or CHA, I'm not going to chase after you about INT or CHA RP unless its way over the top or you have no skills to support your stats. Happy to let the coded systems sort out the truly smart from the average. There are more of these than you think.
However, if you chose for your PC to have below average or bad charisma, I will probably pounce on you if you aren't playing them as below average or bad. If you want to have a weakness in an area that does not enjoy as much coded support as things like combat stats/skills, I encourage you to embrace it and RP it.
When it comes to your artistic creations and performances, however, please DO limit yourself based on the stats that seem appropriate. If your CHA is at M and you have Artistry at E, you should generally be performing at an average level more often than not.
I hope this all makes sense and helps you gauge your RP. If not, let me know and I'll try and answer questions.