akashic-intelligence lost /trekplan Phase 9 twice to reviewer agents that
never returned. Reproduced here and measured: the cause is the Agent tool's
`name` parameter, not the agent definitions.
Passing `name` does not label a subagent - it changes its kind. The spawn is
recorded as taskKind "in_process_teammate" (spawnDepth 0) instead of a real
subagent (spawnDepth 1). A teammate's final assistant text is not a return
value; it reaches the parent only if the teammate itself calls
SendMessage(to: "main"). plan-critic and scope-guardian declare
tools: [Read, Glob, Grep] - no SendMessage - so as teammates they are
structurally incapable of returning, whatever the prompt says.
Denominators: named 0/5 returned; named + explicit SendMessage 1/1; unnamed
3/3 (plan-critic and scope-guardian each returned full findings + the JSON
block in ~110s). Model override 2/2 non-returning, so the override is not
the variable. All 5 named agents produced correct final text in their
transcripts - only delivery failed, and that output is recoverable on disk.
The defect is a harness behaviour, so it is documented rather than silently
worked around: docs/agent-return-channel-defect.md carries the mechanism,
every denominator, the two broken queries that nearly became facts, the
unmeasured cells, and a recommended working shape for consumers (use agents,
drop `name`; do not fall back to inline review, which costs the dedup step).
Prevention is pinned, TDD red->green: the four spawning commands each state
the rule and name the mechanism, and doc-consistency derives the spawning set
from the command files so the pin cannot go vacuous.
Suite 1013 (1011/0/2), +5 from baseline 1008.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014MfB5Ecp8vvGyou8uFGxBV
Kjell Tore Guttormsen
f79c5f6606