Massively worth mentioning. Lots of these phrases seem odd when there is nothing noteworthy but are understandable if you think of the reverse. For example average height, seems odd but that may mean they don't suspect growth difficulties and some conditions would have impacts on growth and height might impact on certain treatments and conditions. If someone was very tall or very small then it would need to be documented, and you are then just making a comment that you have checked that (even if the result was bland!)
Its the same as you might record someone has normal blood pressure, to show you considered that and the result was unremarkable.
Appropriately dressed and well kempt is a good example of this. The opposite would give you cause for concern, if they aren't appropriately dressed that might be due to mental health concerns, memory concerns risks of self neglect, poor housing etc. Its important to note that those warning signs weren't present as it would be to note if they are
Part difficulty is that doctors can be asked questions about the appointment much later when they can't remember the patient at all, both if the patient returns, by other consultants but also in investigations, inquests and coroners hearing.
If someone asks if you were concerned about self neglect, its very hard to explain why you weren't without that "appropriately dressed" bit. If there is a note about being clean, then you would be able to say that as part of your reasoning.
Equally if you are asked a year later in court how someone was in an appointment 12 months ago, pleasant gives you something to go off