Agent SDK v0.16.0

This release improves sub-agent delegation with clearer status reporting, more reliable handoffs, and better visibility into child usage and spend. It does not require a migration and should be a straightforward upgrade for most SDK users.

Highlights

• Sub-agents report clearer status, usage, and handoff behavior
  You get more visible and consistent signals from sub-agent runs, including clearer handoff prompting and usage reporting. This makes it easier to understand what a child agent did and how it affected the parent flow.
• Sub-agent delegation is more reliable and exposes child status and spend
  Delegated calls now surface child status and spend more directly, with improved accounting in parent runs. In practice, this gives you better observability when coordinating multi-agent workflows.

Full changelog: v0.15.0...main