This started as a discussion on chat and it grew into a larger discussion than I anticipated. I'm going to move it over here as suggested by Gung. Here are some links to allow others to follow the original discussion:

However, the conversation mostly focused on what makes an edit "too small" and/or "trivial."

1. Should pleas for help be removed from questions as part of a larger edit?
2. What are the guidelines for a "trivial" edit?
• Personally I find that the main issue is that on Stack Exchange that is no way to indicate that an edit is minor and the edited post should thereby not be pushed to the front page. – Franck Dernoncourt Oct 3 '15 at 22:49

Based on the discussion in chat and here my understanding is:

• Pleas for help should be removed as part of a larger edit, just like "Thanks", and <poster's name/signature>.
• Smaller edits produce benefits (they make threads more readable for future readers, and set a better example of the site's standards and expectations for future posters) and costs (they clog up pages sorted by recency of activity (the home page, user's favourites, etc.), denying attention to more recent questions, or those with new answers or more substantial edits). The benefit/cost ratio is most advantageous if
• A question has high visibility: on popular threads with thousands of views, an edit will benefit many future readers.
• A question is freshly posted, or recently bumped to a high position on the front page: reduces the "costs", as an edit will not bump another thread from the activity page.
• When activity on the site is slow: during busy times, questions fall off the front page very quickly and adding minor edits to the activity stream will only make this worse.
• When you are editing only one or a couple of questions. If you have a large batch of edits you are working through (e.g. as part of a systematic re-tagging), consider throttling your activity by only submitting a few at a time so you do not clog the front page.
• In general when you edit, fix everything you can. If the only fix isn't going to make a worthwhile difference, then think twice, before editing.

Which you should discuss here on Meta before embarking on.

• I added one extra point, re batch editing. Can't remember whether it was mentioned in this chat but it is certainly an issue that has been raised before and there seemed to be fairly clear consensus on. – Silverfish Oct 1 '15 at 23:08
• Any guidance on when exactly activity is slow? (With the time zone indicated, please.) – Stephan Kolassa Oct 2 '15 at 8:04
• Good points. Some suggested others: 1. Edit with a view that people are asking a technical question, so anything that doesn't explain or clarify the technical question should go (personal chit-chat, pleas of urgency or desperation, etc.). 2. It's not the job of an edit to fix substantive errors or confusions, change the notation to one more accurate or congenial, etc. Fixing those often features in appropriate answers or comments. 3. No one is obliged to edit to rewrite very poorly presented questions, which can be voted to close on the grounds that it's unclear what is being asked. – Nick Cox Oct 2 '15 at 9:25
• (+1) for Nick Cox's suggestion. Another thing that I tend to remove is "this is probably a stupid question", "I'm a novice in ...", etc which comes under Nick's "anything that doesn't explain or clarify the technical question" banner. – Silverfish Oct 2 '15 at 17:12
• @Silverfish There is some value to "I'm a novice" in my opinion. This is because the level of abstraction/answer should be adjusted for novices. It might be obvious to you that "Because of ABC it is obviously follows XYZ" but not to me. I agree with your other points though. – Erik Oct 2 '15 at 17:20
• Actually, that's true, it can help future answerers addressing the needs of the OP. As part of a larger edit I will generally strip it out on questions where the OP has already been satisfactorily answered. There's no obligation on answers to reflect the ability of the OP, since answers are for the benefits of future readers too. Here's one of my all-time favourite answers on CV,as an example... – Silverfish Oct 2 '15 at 17:25
• @Silverfish Agreed. – Erik Oct 2 '15 at 17:31
• (Or Nick's comment could be incorporated fairly easily into this answer, this being CW.) – Silverfish Oct 2 '15 at 17:36
• @Silverfish that is what I meant. He should move it into this answer, since he was the one that brought it up. – Erik Oct 2 '15 at 17:40
• I'll mention two circumstances where I think even seemingly trivial edits are worth making: (1) Titles should be correctly spelled, especially with keywords. (2) even in body text, important keywords are worth spelling correctly. This is because people may be trying to search for posts and correctly spelled titles (and keywords more generally) make that easier. – Glen_b Oct 3 '15 at 16:36
• I agree with @Glen_b ... it's also worth pointing out, for those who aren't aware, that the site's internal search feature does not search through comments, only question title, question body and answers. If a keyword appears extensively in the comments and not at all in the body/title then it may be worth editing to include it (though unless this was an especially glaring omission, I'd only do it if there was something else to fix). This is a rare occurrence but sometimes happens in those situations where the OP only reveals what they really want in a comment/ – Silverfish Oct 3 '15 at 22:04
• @Silverfish that's an important point to make, thanks. Either the OP should be encouraged to edit the question to include the important information (good if they're likely to respond), or a kind editor should add it for them. – Glen_b Oct 4 '15 at 1:06