In the context of being assigned because of his body – what is a “vessel”?

What is a tool for a specific purpose:
In regular study of the sign of the checker (we have so far reached section 3, including)
We were wondering – what is a vessel? The Shulchan wrote in section 7, “That does not include vessels such as bundles or stones, even though they are appropriate to cover a vessel with, they are forbidden to be moved.”
How do you define what a tool is?
A. Anything that is appropriate to use is a vessel – it is impossible to say, “Minya” and “Biya” in the same section in the Shulchan Aruch, and also in the Talmud on Shabbat 40. Even though stones and bundles are appropriate to cover vessels with, they are muktzeh.
B – Anything that has something that is used by doing it with the hands – difficult – so is everything that is readable considered mukta? (And it cannot be said that there is any significance to the act of turning the page) and also according to this definition, any object that is intended for decoration (objects whose main purpose is for beauty, such as placing on shelves, etc.)
C- Anything that has a specific definition and purpose (the most logical definition)
Based on this definition, I did not understand why the Mishnav writes (Sekachah) that a lulav is muktzeh because it is not a vessel – why is it not a vessel? According to what definition is it not a vessel? What is the difference between it and the perfumes I prepared for Rah?
What emerges from all of the above is that it is not clear what the definition of a tool is?
What’s especially difficult for me is why is a rabbit (just an example) considered a tool, but a rabbit doll is a tool?
I would appreciate the Rabbi’s answer.