I think the general understanding - although this may differ depending on who you're talking to - is that something is an agent (or is "agentic") if it makes decisions regarding flow, tool use, output, etc. and doesn't just follow a pre-defined path (then it's just an automation).
So, you can make both Agents and Automations in Zapier, Make, Lindy, n8n, etc.
Manus is a different beast from the above, and it is definitely agentic. Although I suppose one could use it to make a simple (non-agentic) automation, but that would seem to be overkill.