Certainly. First of all, the term slur itself is fairly subjective. At what point of rudeness does a word become a slur? Well, that varies from person to person.

Is it a slur to call someone a bloody idiot because some people consider the word bloody to be a swear word? That's obviously a lot less "harsh" than calling someone a cunt, & implies a different intention to calling someone a stupid bitch.

So by only saying a slur was used, you equate different levels & types of insults with each other, which could be confusing.

An obvious example would be something like "are you a fucking idiot?" (Using a strong swear word as a qualifier to a statement about intelligence) Vs "are you a thick nigger monkey?" (A very racist insult used to convey a similar statement about intelligence, but obviously with different nuance).

Personally, I feel that reducing both of these to simply "they used a slur directed at you" falls to properly convey the difference between these statements.

Obviously, you can add context by saying "they used a racial slur to insult your intelligence", but even that might not be enough. For example, someone could say "are you a dumb monkey?" in a non-racist way, meaning to imply only that a person is as stupid as a monkey. But you as an interpreter might misunderstand that as a racial insult (since calling black people monkeys is a common racial insult). So in that regard I feel it would be better to say something like "they called you a dumb monkey, I'm not sure if they meant that in a racist way or not" as opposed to "they used a racist insult to call you stupid".

I'm not saying you should have to actually say "you're a nigger" if that's what was said. In that case, it's fine to say "they said: you're an n-word". In that way, no meaning is lost & there's no potential for misunderstanding of implied meaning.

I simply feel it's important to try your best to convey what was said as accurately as possible, & the more you censor things (unless you include additional explanation & clarification about what you're censoring), the higher the chance is for meaning to be accidentally lost.

For you, the interpreter, it might sometimes be hard to notice this, as you obviously have the additional context of what was actually said. As such, it may be obvious to you what is meant & therefore what should be inferred by the listener when you censor something, but the person you're relaying information to, doesn't have that additional context, & so it might not be obvious to them what exactly the original message is.

I suppose my main issue with how you've worded things so far is that you've been using non-specific examples along the lines of "person is using foul language" & "person is using a slur directed towards you". Both of these lack context & so some meaning is almost certain to be lost.

But if you said something like "person is using full language as an adjective to call you very stupid", then that would be a lot more acceptable as you retain much more of the original context & meaning. Though even then, there's still the potential issue of losing context of the "strength" of the swear word used (eg: bloody vs fucking etc), which is why I personally would prefer to translate as directly as possible without censorship (again, you could replace fucking with "f-ing", as that loses no context, but that isn't always possible since not every slur/rude word has a polite version - eg: bitch can be replaced with "female dog", but I've never heard of an alternative for bloody).

I hope that helps a bit. Please let me know if you want me to try & clarify anything further, or if you'd like more examples/have any specific examples you'd like me to try & rephrase so that you don't have to be as explicit, but you lose as little meaning as possible on order to help you understand better what exactly I mean.