For the sandbox wiki, I think best practice is to create just one entry (say Zappanale or Zappanale-Sandbox) and not one for each item or draft that you're working on.
I'm not exaggerating when I say your best bet is to read a few hundred SCP entries to get a feel for the tone. There are quite a few really popular entries that did something wacky with the traditional format that you shouldn't imitate which makes just looking at the most popular "dangerous", but seriously at least go through the first 100 or 200 and you should get a good feel over all for what they should look like.
The guides are assumed reading, and I've found these to be interesting supplements as well:
Just going over a few things that stick out at me (and keep in mind I'm a noob so grain of salt and all that);
SCP-NUMBER should be used and not SCP NUMBER, SCP, or NUMBER.
If you use measurements, make sure to include units and they are in metric. (e.g. 5x5 cell)
"imaginative use of seemingly non-dangerous items" is pretty flowery language. SCP entries should be more clinical.
"is a human, or at least, once human, creature of an indeterminate age" isn't clinical.
If you go over the data-redacted guide just above you should be able to figure out the issues with the redactions in the second paragraph of the description.
The rest of it lacks a clinical feel to the description and wanders into run on sentence territory with all the commas. Rephrasing the sentences to be shorter would be good, as well as dropping unimportant descriptive text. Descriptive text in tales or short stories is good, but in SCP entries it's usually a bad idea.