datapoints.read returns the latest value of a slug the role reaches, at the
bridge’s capture time. datapoints.history returns recorded values and can
bucket the series. History needs the same access as the latest value, and a
datapoint that does not record answers not_recorded.
Find robot_id and the slug with robots.list and robots.describe. Call
docs.describe for each action’s required fields, filters and refusals. Role
changes apply to the next call, even in an open MCP session.