I agree. Seems like this would save many newcomers from asking questions which get closed for being off-topic or belong on a different site, if they could easily see the rules about questions on the site on the sidebar, at least as a link. It is non-obvious where to look on sites if you wish to look for the rules of the site, and it would only take up a little bit of space from a UI perspective. If it matters from a clutter perspective, it could go away after some amount of reputation on the site.
For example, let's say I want to know what's on topic for philosophy. I go to the homepage for the site and find no links telling me general information about the site. OK fine, so, I go to ask a question, and I see "Find more information about how to ask a good question here." It does not say what is on topic. And it is a rather vague page which contains 6 links. (This isn't about the philosophy site at all, they are universally like this, verbatim, in my experience.) Two of the six links contain the rules on what is on topic, but they're longwinded, and I doubt many newcomers will care that much to navigate to multiple pages by this point. They'll probably give up and risk asking the question anyway. This is bad for experienced users, who don't like off-topic questions, and is bad for the newcomer who may have their question closed and had a genuine desire to find the rule before asking.
Shouldn't the rules for what can be asked be linked somewhere on the homepage, before someone already commits and clicks on "ask" (where they are linked on the sidebar)? Even better, we could just have a quick summary on the sidebar. For philosophy, maybe it would look like:
You can ask about philosophical topics such as epistemology, logic, history of philosophy, applied philosophy, etc.
However, you should avoid:
- questions that are very common and likely to be answered in many other places.
- questions that just express your own beliefs.
- asking a question if your goal is discussion, rather than an explanation.
- asking questions where the answer would be entirely subjective, even though it is okay to ask some subjective questions.
Adding at least a link (or better, an expandable dropdown) seems like a no-brainer to me, and this exists on many other Q/A sites.