Object class:
Every word in a section header should be capitalized as per the standard template. Divergences from this template can be made for storytelling purposes, but unless there's a clear reason to diverge you should generally follow the template.
All containment cells are located together on site [redacted] in area [redacted].
Redacting information in the containment procedures is generally frowned upon. In-universe, it complicates the ability of anyone to recontain objects in the required places. Out of universe, it generally feels a bit like lazy writing to redact anything that wouldn't be necessary to react. Again, this is something you can do for specific purposes, but doing it spuriously risks downvotes for it.
If an incident were to occur where SCP-XXXX becomes violent because its host or itself feels endangered all staff must distance themselves from SCP-XXXX. SCP-XXXX must be contained as soon as possible so it can be sprayed by a foundation made herbicide. This substance has been designed to temporarily disable SCP-XXXX's abilities during containment breach.
Nothing in this paragraph feels necessary except for the herbicide spraying. Being concise and precise helps maintain clinical tone, so I would recommend shortening this to simply say that the anomaly should be sprayed when it breaches containment. If you want to create a bit of detail to give the impression of in-universe accuracy, you could mention a name or intensity of the necessary herbicide.
Its hosts are all humanoid entities that appear female with roman numerals 1-4 on their foreheads.
The overuse of the pronoun "its" gives this paragraph a somewhat sloppy feeling. I would recommend simply using "SCP-XXXX" when possible.
These four entities provide SCP-XXXX other no benefits besides a body to operate
How does the Foundation know this? As the author, you know everything, but the in-universe can only know things it can plausibly have discovered. Concretely establishing this fact seems difficult.
They can focus on something they take interest in for days or even weeks, but not once have they ever needed to rest.
This sentence just repeats the information in the one before it. Being concise is important throughout the document, and it's boring to the reader to see the same thing multiple times.
Their skin is similar to porcelain but much more durable. As for their clothes, there isn't much to say as it looks like normal high-quality fabric, but they cannot be removed.
This feels overly casual. How durable is their skin? In what ways is it similar to porcelain? Instead of making the comparison, just give the reader the information that justifies that comparison. The same is true of whatever the quasi-fabric is.
the various -letter instances
Without the full interviews you seem to be planning, I'm having difficulty judging these. I would recommend writing those interviews/incidents, then cutting out the overlapping information from their descriptions.
