Note: I correct the given mistake only once. If you do not use the metric system, I will only make a single comment about it, even if it appears again in the rest of the article. If the draft has many language problems, I will only correct the most glaring ones.
SCP-3000 can be stored in any high-security humanoid containment wing.
I recommend rephrasing, because the wing includes outside of cells, and the 'can be' part implies that it's not actually contained right now.
A staff member is to be sent into the containment wing once a day. They are to ensure that SCP-3000 performs forty minutes of light exercise. Following this, they are to inspect SCP-3000's coat for matted hair or overgrowing nails. These should be removed appropriately.
I usually say that people should avoid making sentences too long, but I recommend the opposite here. It's a bit too choppy here:
''SCP-3000 is required to perform 40 minutes of light exercise daily. Following this, its coat and fur will be inspected for matted hair or overgrowing nails and removed appropriately when found.''
Why are we checking for overgrown nails daily anyway? We can probably assume that its nails haven't overgrown in the previous 24 hours.
SCP-3000's diet is to be controlled.
That's to be expected, right? We won't allow it to forage itself.
These are typically available in the form of beet pulp or flaxseed but may differ from site to site.
Capitalise 'Site'. Also, it's fine to be specific:
''SCP-XXXX is fed 85g of dog food daily, with additional fiber-rich beet pulp of flax seed (specify the amount).''
However, the subject's face and head have undergone significant surgical alterations. The creature's eyes, teeth and jaw bones have been removed and replaced with that of a human.
Don't say 'the creature' or 'the subject'. Designate it 'SCP-XXXX' or 'it'. This is true for the whole draft.
The most common communication from the creature consists of requests for food or complaints of hunger. While the creature claims not to feel hungry,
It literally says that it's hungry in the first sentence, but that it claims it isn't in the next.
This indicates that these feelings of hunger are significant enough to countermand feelings of shame, disgust or pain.
I mean, I've seen dogs eat stranger things. People eat ice cubes too. Some people even eat wood, but that's the strangest thing of the three.
Furthermore, it claimed knowledge of a personal issue in Agent [Data Expunged] that the inquiry had previously found used as a means of extorting Agent [Data Expunged].
I'm going to recommend reading Zen And The Art Of DATA EXPUNGED, because this looks removed for the wrong reasons. Censoring on the site is used as a narrative device. It makes the reader wonder what was horrible enough to be removed like that. That is, if you give them the right clues. If you remove it without proper context or hints to what something might mean, it instead looks like you didn't know what to write here.