Andrew's answer deals with your sentence well and ought to be accepted (in my opinion), but I'll just use the occasion to address the more general question you asked.
There is a long history in English style of recommending concision. For many authors, no further authority is needed than that of Strunk & White's Elements of Style, because most modern style guides have either built on or made allusion to that work anyway. In their section "Omit needless words" (scroll down on this page), they give a few examples of corrections to make:
the question as to whether → whether (the question whether)
there is no doubt but that → no doubt (doubtless)
used for fuel purposes → used for fuel
he is a man who → he
in a hasty manner → hastily
this is a subject which → this subject
His story is a strange one. → His story is strange.
I can't find a particular reference for individual word length, but their philosophy makes it plain that they would also recommend using shorter ones when possible:
Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts.
Presumably a word should likewise have no unnecessary letters.
But a key part of this advice is often given too little weight despite being intuitively correct:
This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell.
That is, this principle requires that every word contribute to the meaning.
This is a good principle. However, some nuance can be added. (Actually, Strunk & White, while a good manual of style for most, sometimes rankles those who can reliably judge style themselves, and it's not useful as a grammar reference.)
Besides stressing once more the "no unnecessary words" part of the advice, the main caveat I would add is this. It's quite possible to reduce sentences to gnomic, pithy kernels of their meaning. Since I have experience editing for a newspaper and reviewing beginner code, my instinct is to do just that: reword, delete, simplify. But this doesn't always achieve the purpose of a text, which is clear communication.
An example from programming might be useful. Take Java. According to the grammar of the language, all that is necessary to distinguish meaning is that names be unique. Thus, a class could have properties and methods named a, b, c, and d and comply with this grammar. The compiler certainly would not complain. It would have no trouble understanding you perfectly. If you ran out of letters you could start to use aa, bb...
But it would not be readable by humans! So you might allow yourself to sacrifice some concision in return for clarity and settle on ts, temp, updateTS, readTemp. This is still fairly concise, and the extra letters help you guess what you're doing.
But still... it's only understandable to someone who already has an idea of what you're trying to do. What do you often find in the real world? Try timestamp, temperatureInCelsius, updateTimestamp, readTemperatureInCelsiusFromThermometer, and so on. The conventions, in light of the need for comprehensibility by someone who may never have seen the code before, often favour verbosity over concision.
The same idea applies to English. There is a certain ideal, crystallized style in which no words are wasted. It feels wonderful to chip away at a sentence till you have such a style, using the most precise words, and there's a certain satisfaction in understanding such a sentence. But if you ever have to choose between that concision and being absolutely sure that your meaning gets across, choose the latter.
To illustrate this point, here's a concise sentence:
Popular films infantilize if they fail to distinguish consciousnesses.
Here's a verbose version:
Hollywood movies make us more childlike as viewers when they assume that our experiences of the world are totally shared, not distinct — that is, when they implicitly deny the theory of mind developed early in our childhoods.
Which sentence did you get more out of? The second is just paraphrase of and extrapolation from the first, and is several times as long. But in a textbook, the first one will either be read three times by an attentive student or skimmed over by an inattentive student, however elegant it is as English.
This is more extreme than the example you cited, of course, but it should give an idea of the value of unpacking your thought. By all means, aim for short sentences and chip away at unnecessary words; the world has far too many of them. But meaning isn't the only baby to avoid throwing out with the bathwater — its twin is the ability to be widely understood.