We could use the obvious syntax `sortby:OPTION`, where `OPTION` is one of:

    Relevance
    Newest
    Votes
    Active

All it would take to implement this would be to insert `tab=OPTION&` after the question mark and before the `q=MYQUERY` in the URL that is generated when searching for `MYQUERY`. Example: to automatically sort by `OPTION` when `MYQUERY sortby:OPTION` is entered into the search bar, just turn

https://meta.stackexchange.com/search?q=MYQUERY

into

https://meta.stackexchange.com/search?tab=votes&q=MYQUERY

where `MYQUERY` is just some place-holder text for an arbitrary query (so I'm not actually trying to search for the text `MYQUERY`).

For example, lets say that I want to search for the word `works` and I know even before searching that I want the results to be sorted by votes. Currently, in order to do this I have to search for `works` by using the search box (which leads me to the page https://meta.stackexchange.com/search?q=works) and then I have to click on the "Votes" tab (which leads me to the page https://meta.stackexchange.com/search?tab=votes&q=works). What I'm envisioning is that whenever the text `sortby:votes` appears within the search query (e.g. if I search for `works sortby:votes`) then I am automatically led to the page https://meta.stackexchange.com/search?tab=votes&q=works (in contrast, currently a search for `works sortby:votes` leads to the page https://meta.stackexchange.com/search?q=works+sortby%3Avote).

Heck, adding these two other options:

`page:PAGENUMBER` and `pagesize:PAGESIZE`

(both of which are also missing and would be appreciated) would be even easier since you literally just change the `:` into an `=`, add an `&` to the end, and then insert the resulting

`page=PAGENUMBER&` and `pagesize=PAGESIZE&`

after the question mark.

Of course, ideally `PAGENUMBER` is a valid page number that it automatically loads on and `PAGESIZE` is one of 10, 30, or 50, but what if it isn't? What if someone enters into the search box

    Please Improve Search page:TrAsH sortby:JunK pagesize:GarBaGe

Will anything break? NO! Just click the theoretical resulting link yourself:

https://meta.stackexchange.com/search?page=TrAsH&tab=JunK&pagesize=GarBaGe&q=Please%20Improve%20Search

Any invalid input is *ALREADY* automatically ignored and set to its default.

On the other hand, for some valid search query, such as:

    Please Improve Search page:2 sortby:votes pagesize:30

everything would work exactly as expected since the resulting link would be:

https://meta.stackexchange.com/search?page=2&tab=votes&pagesize=30&q=Please%20Improve%20Search

(note that it worked even though `votes` began with a lower case 'v' rather than an upper case 'V').

This is a little thing that would improve Stack Exchange, especially when using the search feature to find out whether or not your question has already been asked or answered. In particular, it would help by making it easier to wade through the sometimes hundreds or thousands of search results that are returned by making it faster and easier to repeatedly change or refine your query without having to find your old location in the search results over and over again.