IF: What are the criteria for deciding if additional information or input is relevant to the circle when making a decision?

It really depends on the moment, the experience level and level of trust in the group. Additional information or clarification is essential if no next step can be made without that information. E.g. if a proposal is not understood enough to be approved, then additional clarification is needed.
Issues arise when there is no agreement within the group on whether additional information is needed; for example when one part of the circle wants to move on but the others still want to explore additional information. Here, it depends on the scale of this issue. For moments with high significance, the proposal to move on can be objected to, and those objections should be integrated (also because this affects how the timing of the agenda works out). For minor issues, the facilitator might decide whether additional information seems relevant.

For more information, check out our handbook Many Voices One Song section 5.5