Basically, this ‘safe’ 4th dimensional library
Can you define "4th dimensional" in this context? It just feels like sci-fi jargon here. Is it just in a different dimension? Its own dimension?
However, there is a twist, and comes when the researchers delve deeper into the library to find a section dedicated to all of the the foundations documents and findings held within filing cabinets. Any paper copies created by the foundation is held within the library bumping up the object class to Thaumiel.
How many paper copies do you the The Foundation keeps of really sensitive materials? How does this make it Thaumiel? It doesn't assist the Foundation in containing other SCPs, it just keeps a backup copy of whatever information they have on paper.
What limits it is how much the material is made of plant (wood) and/or carbon, for example, The tree (which would be labeled SCP-XXXX-A) can only copy the wood handle of a saw because the tool is about %30 metal, however it can copy a hammer in its entirely.
What determines this percentage? Overall mass? Because the metal head of a hammer comprises more of its mass than the wood handle because the metal is much more dense. And what's the actual specific % makeup cutoff?
Like all libraries, this SCP will also have a librarian that is capable of pulling out anything the person needs at his/her request
All libraries have this? Since when? I mean I haven't been to a library in a while but damn that is an upgrade!
the librarian is also capable of teleportation via doorway with anyone to whatever he/she desires. But, it has to be a thorough description or the librarian would be unable to fulfill the request.
I'm confused about what this sentence is trying to convey. The librarian can teleport anyone anywhere as long as there's a doorway and they can explain the location well? This seems like something The Foundation would definitely try to exploit for easy travel over large distances.
due to the tree's carbon sequestration
What is carbon sequestration? Your summary probably shouldn't send people to Google to understand it.
Normal SCP researchers will have access to the library for testing but D-class will not be used. Standard security personnel will also be required to prevent any trespassers, due to the tree's roots it is impossible to relocate the library to any nearby Site's.
Why no D-Class, even before the find the Foundation documents? What are they afraid of them finding there?
This discovery would create paranoia within the upper echelon causing not only the security procedure to escalate to maximum, but for the file itself of the SCP will also be rewritten to become a false document, the real one will only be viewed by high ranking, to everyone else it will be viewed as just another SCP. To add to the paranoia a countermeasure is also created to prevent anyone else from gaining access to the SCP if containment should fail.
Why? If they have this thing contained it seems easy to set up a small outpost within the library to guard that information the same way any other SCPs are guarded. Why have a fake article at all, why not just make the whole thing be high security?
SCP-XXXX-A is also capable of copying certain SCP's, however most would either not retain the original ability or will be in a vegetative (but alive) state due to them not having a mind. That includes SCP's such as 085, 805, 1010, 1516, etc.
This just seems like unnecessary cross-linking, and see my later comment about carbon-based life forms.
I will also dedicate a section to clarify that this SCP is in no way nearly as powerful as the wandering library as the SCP is only capable of copying things that ‘exists’ and within this reality/dimension.
Having a whole section devoted to "No really guys it's different" feels kind of indicative that it's….not?