I think most of us have had experience, over the years, in assessing this difference. It can be complicated.
For a very simple example, I might say that somebody who has a plan to harm themselves has a timeline in which they would do it, has a means of doing so and is expressing it. It's having a kind of intuitive reaction to a negative factor in their life. They might be seen as someone who is acutely suicidal.
Somebody else requesting MAID might come in and tell you they've been talking about this with their family for months or years, and explain what their disease trajectory has been, what their values are, why they believe there's no longer any meaning in their life or why they might want to choose to end their life. They would be willing to work with the team and the clinicians to see whether that's a possibility for them, or whether there are other resources available.
There's a distinct difference between the two.