SCP Foundation

Members of the janitorial staff are to pretend to listen to its stories while performing their duties, then politely inform SCP-4251-1 that they must be on their way, but promise to resume where it left off next time they come over.

I'd cut this down to 'Members of the janitorial staff are to listen to its stories while performing their duties.

Audio recording devices should be kept in its chamber in case it decides to boast of any more of its "history" or otherwise reveal any more information about itself.

This isn't clinical tone. Honestly you can probably delete this part.

SCP-4251-1 is to be kept in a furnished room along with its current host, SCP-4251-2. It is not to be allowed near anything sharp, or anything that can be used as a shield. It also should never be informed of any SCP that may resemble "a challenge" in any way without approval. Books and music are acceptable ways to keep it and its host entertained. Television is not advised in case of any attempts to replicate what it sees on television, as demonstrated after it watched X███: W██████ P███████ and attempted to replicate the stunts and battle cries performed within the show.

You can trim this down a lot, maybe something like "SCP-4251-1 is to be kept in a standard humanoid containment cell and to be allowed to visit the rest of the facility. No televisions are to be allowed in SCP-4251-1's cell to avoid it attempting to imitate what it sees on television". Or something. You don't need to mention keeping it away from other SCPs because that's implied since the Foundation wouldn't let it go near another Skip without permission anyway.

After reports of metallic noises in a home in ██████ France, local police had found its elderly resident deceased of natural causes and wearing an embellished suit of armor. The armor removed itself from the deceased man and began to try and latch itself onto the police officer, who escaped. It was sometime after that the Foundation was contacted and field personnel was sent in. It attempted to latch onto several of them but was captured using a decoy mannequin in a large metal crate. It was unable to control the mannequin, revealing that it needed a living host.

The Description part is my biggest issue with this skip. Usually the Description and Discovery of the SCP are split into two sections. You combined them for some reason. What you should do instead is. Set it up like:

Description: "Describe it here."

Discovery/Acquisition/Recovery¹: "Explain how the Foundation first encountered it here.

After transports, SCP-4251-1 was put into an isolated chamber, and D-6531 was sent in to investigate the effects of the armor on a host. It proceeded to latch itself onto D-6531, at which point the armor could be heard vocalizing pleasure in finding "a suitable comrade" and then attempting to challenge security to battle, at which point a few guards were sent in to restrain it. After approximately eight minutes, the suit conceded a "draw", claiming it did so to prevent its host from being further damaged, insisting it could still have defeated Security Personnel, prompting disapproving groans from D-6531.

Why was a D-class sent to investigate?

SCP-4251-1 has given multiple backstories, including… and finally,

This part is pretty good, but maybe move it to earlier in the article (as in before the Discovery section).

Interviewer: Dr. █████
Interviewee: SCP-4251-1

You should Bold the researcher and SCP's names.

Other then that one big thing is that you need to work on making the tone of the story more clinical. As one example:

Mentioning this offended SCP-4251-1 greatly, putting it into a depression, and it was days before we could convince it to talk to Dr. █████, at which point it seemed to have forgotten the incident altogether.

Should be changed to something like: "Mentioning this offended SCP-4251-1 causing it to display symptoms of depression. It refused to talk to any Researchers until several days later when it was convinced to speak with Dr. BLACKBOX" or something.

You can read more on clinical tone here.

Anyway, in conclusion I would like to say something. I really, really hope this SCP becomes a mainlist skip. Because while there are issues in your draft the story itself a very much enjoyed. Good luck!

As a final note you can find more reviewers to help you with this here.