How do I make these sentences better?

Saying "But anyway" is akin to having a personal conversation with your audience, which, in this case, you're not supposed to be doing. You should be establishing the scenario.

To say "this blade" is specifying it as a phrase where you are presenting a blade to the reader, which you aren't. Simply omit the "this", replace it with an article, like "a" and you'll be fine.

And while putting "..." as a pause before "dirty blonde" is a signal for a pause in speech, in a book, it gets irritating, because the reader wants to know how the character looked like. If you want to be unsure, you could say, "his short hair was a dark, almost dirty blond" (Notice my spelling of "blond". You drop the following "E" if you're referring to a male) You should drop the question mark, as it makes it seem as if you are asking a hypothetical question to the reader, and might confuse them.

You could also use more description. Was his hair well-trimmed, hastily brushed, or unkempt? How short is it exactly? Were his blue eyes deep and mysterious, light and empty, or bright and energetic? These are things that help a reader visualize the character, while still allowing them to create their own mental image.

To use all this advice, I would phrase the sentences in this way:

"The valet stood at about 5'11. His short and dark, almost dirty blonde hair was neat and tidy, put together in a uniform fashion that one would expect from one trained in his occupation. His deep blue eyes were cold and reserved, and he always carried a blade with him, it was long and silver."

Of course, I took liberty as to his appearance, you can change his description in your book, but you can see how much more immersive it became, and more descriptive. Try it out yourself. It may take longer to write, but trust me, the quality delivered to the readers is worth it.