The full and official verbiage defining how the Anatomically Correct tag should be used can be found here: Anatomically Correct Series. But there are some aspects of it that I think deserve some minor revisions.
Suggested Changes 1 & 2
Creature descriptions (1)should include important behavioral attributes (2)and a clear physical description.
... should read as either ...
Creature descriptions (1)must include important behavioral attributes (2)or a clear physical description.
... or ...
(1)It is best if creature descriptions include important behavioral attributes (2)or a clear physical description.
The reason for suggesting that "should" be changed is because "should" is often interpreted differently depending on who you ask. Depending on how an individual processes pragmatic language, "should" will either mean it is a mandatory rule like when a mother says, "You should always brush your teeth before bed.", or it could be read as a an optional suggestion like you "You should check out this new movie!" So, when writing things that are meant to be taken as rule, "should" is always best avoided because it creates confusion and conflict. So first we need to decide if this was even meant to be an optional or mandatory requirement, and then clarify it accordingly
My reason for suggesting we change "and" to "or" is more significant IMO. When discussing the anatomy of a fictional creature, you need a goal or there is no question. If you know the behavior, then you are probably asking about what physical characteristics would support it. If you know the physical, then you probably need to know about what behaviors would correspond with that body plan. In fact, I went through the Anatomically Correct series listed, picked 5 random creatures and all 5 questions would fail this criteria because they either did not establish the creature's physical or behavioral characteristics, all 5 were asking for help to derive one from the other.
When you know both in good detail, chances are, you're just asking for an open ended critique which will inevitably fall afoul of one or more vote-to-close criteria.
Suggested Change 3
(3)The best answer is expected to be the one that provides the greatest detail, the greatest creativity, and the greatest capacity for suspension of disbelief.
... should read as either ...
(3)The best answer is required to be the one that provides the greatest detail, the greatest creativity, and the greatest capacity for suspension of disbelief.
... or ...
(3)Unless otherwise specified, the best answer is expected to be the one that provides the greatest detail, the greatest creativity, and the greatest capacity for suspension of disbelief.
This is along the same lines as the "should" issue. As it is, it is unclear if this is meant to be the default assumption if no criteria are given in the question or if Anatomically Correct questions require the OP to use this as the basis for a best possible answer.
(AFTER FURTHER THOUGHT)
The more I think about it, I think the best approach to #3 is actually a more significant rewrite.
Answers must provide a good capacity for suspension of disbelief.
The greatest detail and the greatest creativity are certainly factors that can and should impact the best answer in many cases... but a brief or "overused" answer can still be the best answer when talking about anatomy.
I think the real point of this rule is that it the OP must be looking for an answer that provides a good capacity for suspension of disbelief for "anatomically correct" tag to make any since. So an answer that just arbitrarily says that a dragon flies using magic is obviously not actually addressing the anatomy of the dragon, and I think that is what needs to be avoided when using this tag.
Used thus, I could see this rule being very similar to the Science Based tag where the use of the tag implies something about the importance of reality based credibility being an expectation.
My personal interpretation of the rules are that the changes should be (1)"...must...", (2)"...or...", and (3)"Answers must provide a good capacity for suspension of disbelief."