A delegated subagent that exhausts its per-child iteration budget
(delegation.max_iterations) still returns a summary, so the result carries
status='completed' even though the child's exit_reason is 'max_iterations' and
its work was cut off mid-task. The parent then reads 'completed', trusts the
partial summary, and only discovers the truncation by parsing the prose (where
the child happens to mention 'hit the iteration limit'). That wastes parent
turns and risks acting on incomplete work.
exit_reason is already computed authoritatively and threaded to every
parent-visible surface; it just wasn't reflected anywhere the parent reads at a
glance. This surfaces it:
- delegate_tool.py: add a parent-visible boolean 'truncated' (= exit_reason ==
'max_iterations') to each task entry, alongside the existing exit_reason.
- process_registry._format_async_delegation: for both the batch and single-task
paths, when truncated -> use a warning icon, append
'TRUNCATED: hit max_iterations — work may be incomplete' to the header/Status
line, and prefix the summary with an unmissable truncation notice. status
semantics are left unchanged (stays 'completed') so existing icon/summary
branch logic and ~10 tests asserting status=='completed' stay valid.
Tests: single-task truncated -> banner; single-task clean -> no banner; batch
marks only the truncated task, not its clean sibling. 23/23 in the async-
delegation suite.
Co-authored-by: Teknium <teknium1@users.noreply.github.com>