Grades fast-model activity-label headers against a fixed corpus so
instruction changes are measured rather than eyeballed on one
conversation. This existed untracked while the continuity work was
developed; committing it because it is the only reproducible record of
WHY `ACTIVITY_INSTRUCTION` is ordered and capped the way it is.
- captured.json: 9 real production payloads pulled verbatim from Langfuse
with the headers that shipped. Irreplaceable — traces age out.
- corpus.js: 17 cases / 28 steps. The captured run replays as one
sequence, plus synthetic cases for the modes it never exercised
(all-failed, partial, parallel batches, rapid near-duplicates, entry
overflow, truncated output, error-shaped success). Multi-step cases
chain each generated label into the next step's context, which is what
makes cross-batch redundancy measurable at all.
- prompt.js: faithful port of the SDK's buildActivityLabelPrompt so
synthetic cases render the bytes production sends, plus a
previousLabelCap knob for continuity-window experiments.
- variants.js: single-factor instruction variants. The baseline is read
from the BUILT package (workspace resolution, then dist, then
LABEL_EVAL_DIST) so a variant can never be graded against a stale copy
of the shipped instruction.
- checks.js: length/punctuation/markdown/tool-echo/count-echo, plus
overlap split into `restate` (adds nothing over an earlier header) vs
`template` (same frame, new payload — often fine).
- run.js / rescore.js: live runner on the production wire shape
(max_tokens 256) and an offline re-grader, so metric fixes never
require re-spending on the API.
Results are gitignored — regenerable, and 292K of the 364K. A full sweep
is ~$0.03 per variant and ~45s.
Findings are recorded in the README, two of them counter-intuitive:
enumerating acceptable opening verbs ANCHORED the model rather than
diversifying it (Confirmed 18→23, opener diversity halved), and diverse
examples alone changed nothing. Sentence order is load-bearing, so a
tidying reshuffle of ACTIVITY_INSTRUCTION regresses real output.
