I think specifically we want a plugin to be able to indicate if it's safe for it to be triggered without the user's direct consent, and then the user themselves can also override any plugin to force it to need user consent or not.
For example, if we have a plugin that can fetch the weather for a single city, and a user asks "Where, in the top 20 cities, is it the hottest?", I don't think we want 20 prompts. I think the weather plugin can mark itself as "I cannot do anything dangerous, just call me, no worries".
On the other hand, the zappier plugin, which can access email and perform proper actions, should be able to indicate "all these APIs are sensitive"
You might want to have a mix, where the weather plugin has "GetUserOwnCityWeather" (requires permissions / user intent), and "GetAnyCityWeather" (public, no user intent required).