Per-call accounting of prompt capacity so we can answer 'does
context size affect strict-rate?' at aggregate scale.
Per-call result dict gains:
"prompt_chars": {
"system_prompt": <int>, # system message chars
"grounding_reminder": <int>, # restated rule message (if any)
"user_question": <int>, # the original question text
"evidence_or_context":<int>, # rendered evidence map / wikitext context
"messages_total": <int>, # sum of all messages[].content
}
"answer_chars": <int> # rendered answer length
Char-level for now: model-agnostic, fast, and a workable proxy
for prompt tokens (~4 chars/token English prose, ~2.5 for JSON-
evidence-block heavy contexts). Token-exact accounting can layer
on later if a tokenizer is cheap enough to wire in per-call.
Surfaces in three places:
(1) result["prompt_chars"] — for programmatic callers. Cache hits
return prompt_chars too (computed before lookup).
(2) `aborist query` human render — one-liner showing the breakdown
and the answer length, so an operator can tell at a glance
whether STRICT came from a 5KB tight prompt or a 60KB stuffed
context.
(3) bench/qa_sweep.py — per-row prompt_chars_{total,evidence,system,
question} + answer_chars columns in the JSONL, plus a new
"strict-rate by prompt size" section in the markdown summary
bucketing runs by capacity (<8KB, 8-16KB, 16-32KB, 32-64KB,
>=64KB) so the bench reveals whether input size correlates
with verdict quality across modes.
Never enters cache_key — runtime measurements, not policy.