- _transcript_row_texts re-implemented agent.message_content.flatten_message_text
and the api_content sidecar rule; the note can only land on a user row,
so the transcript scan now skips assistant/tool rows (the bulk of the bytes).
- Three sites computed "names of agent.tools"; tools.mcp_tool_agent gains
agent_tool_names() used by the switch note and conversation_loop, which
also stops importing the private _def_name across modules. The name list
is only captured when a switch was announced.
- split_runtime_boundary() is the single owner of the runtime-block
rpartition/END check for both identity_line_value and
_stored_prompt_matches_runtime.
- platform_surface_hint was a public alias of _platform_hint; the function is
now platform_hint (its docstring pointed at the pre-move module).
- consume_gateway_turn_context_notes and consume_surface_switch_note share
_pop_turn_note so the two one-shot channels have identical semantics.
- platform check hoisted above the transcript scan.
Move the six surface-switch helpers out of the conversation_loop facade
into agent/surface_switch.py (AGENTS.md: new behaviour goes in a topical
sibling), and fold the review findings on #104494:
- MoA and codex_app_server turns never stamp the api_content sidecar, so
the staged note could not be read back from the transcript and was
re-sent on every turn after a switch. Those modes now skip the note
(stored prompt still reused).
- The announced surface was parsed with split(".") — a plugin platform
with a dot in its name would never compare equal and re-stage the note
every turn. The note now closes the name with a fixed terminator.
- One identity-line parser (identity_line_value) shared by
_stored_prompt_matches_runtime and the switch detector instead of two
copies of the runtime-boundary/rpartition logic; tool names via the
existing tools.mcp_tool_agent._def_name; the transcript scan is bounded
to the last 200 rows (it ran every turn over the whole history).
- consume_surface_switch_note reduced to a plain pop; developer-guide
prompt-assembly.md updated (Platform is no longer an identity field);
17 new tests trimmed to 10 (same-shape pin/retire variants folded).
Restoring Platform as an identity field still turns 5 tests red.
