What
When a subagent tries to spawn another agent beyond the nesting depth cap, it now receives a clear error message explaining what happened and instructing it to complete the task directly.
Details
- Error: "Subagent nesting limit reached (depth N of M). Complete this task directly using your tools instead of spawning another agent."
- Previously this situation could fail silently or produce a confusing error
Evidence
New depth-cap error (search for "Subagent nesting limit reached")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.