A decision is a question that needed a person. It carries the question itself, the alternatives considered, a confidence, and links to whatever it touches - products, tasks, epics, incidents.
Advisories are proposals, and only proposals
An agent can create a decision, frame it, weigh the options and post an advisory: its recommendation, its confidence, and the evidence behind it. Several agents can advise on the same decision and disagree.
None of that resolves anything. Exactly one act ends a decision - decide_decision - and an agent principal is refused it, always, no matter what its token grants. It is on the deny-list, not behind a scope, because a scope is something you can grant by accident.
That single rule is what makes advisories worth having. An agent that could resolve its own decision would make posting an advisory decorative.
What gets recorded
When a decision is resolved, what lands is: who decided, when, the outcome, the option chosen, and the rationale. That record is append-only. A later edit to the surrounding context does not rewrite it, and it is still there when someone asks in eight months why this was done.
You can also set a reviewAt date - a decision you expect to revisit rather than one you consider closed forever.
Blocking
A decision can block work. Link it with role: "blocks" and the linked task or epic is held until the call is made. An agent can create links; it cannot remove a blocking one, because otherwise an agent whose task was blocked could release itself in two calls.
Design reviews
A visual review is a decision with pictures: typed mockups, comments anchored to specific elements, and advisory votes from whoever is reviewing. Same resolution rule - the votes advise, a person decides.