The doc is open. Six people have commented. Two comments contradict each other. One is a question that never got an answer. The owner of the doc writes "I think we're good" in Slack. A month later nobody can say who chose the vendor, or whether the comment that said "no" was resolved or ignored.
A shared document is a place to build. It is a poor place to decide. Decision-making in the margin produces a trail of thoughts and no signature.
Comments do not transfer ownership
A decision moves the outcome to the person who picks. A comment does not. It is an opinion with a timestamp, attached to a sentence that may be rewritten tomorrow. The person who commented did not agree to be accountable. The person who wrote "resolved" in the UI did not record a pick. They tidied a thread.
"Please look at the doc" is the shapeless ask wearing a URL. The reply will mirror it: more comments, a thumbs-up, silence. None of those is "B, and I will tell the vendor."
If you needed a decision, you never asked for one. You asked for attendance in a file.
The doc is indexed to the people already in it
A comment thread assumes the reader has been living in the draft. The person you actually need — the signer, the counsel, the cofounder who was travelling — opens a forty-comment file and has no idea which argument is live. They add a forty-first comment, or they bounce.
Ask for the decision on a page composed for them. Closed options. The one rejected path that they will otherwise reopen. The assumption that would change the pick. A note you approved. Link the doc only if a figure in it is one the pick depends on, and quote the figure. Attachments are out of scope; a URL to a living file is the same hazard in nicer clothes — the bytes will move after they "agreed."
Agreement in a doc has no later shape
When someone asks, in six weeks, what you decided, the honest answer in a comment culture is "search the doc." That search is an interpretation. Two people will find two different comments and both will be sure.
A briefing leaves a package: the ask, the pick in the reply, the labels on who wrote the note. You can open it. You can show it. You cannot pretend a resolved comment thread was the same object.
Use the doc for what it is good at
Write the spec there. Collect the defects there. Let the people building the thing argue in the margin. When the argument is done, someone still has to ask — in a message that can be answered without opening the file — who owns the outcome.
If the doc is the only place the question exists, you do not have a decision process. You have a draft that people visit. Visit is not a pick.