---
type: eval-results
title: os-vault write eval — untuned baseline grid (unprompted vault-write discrimination)
summary: At baseline (no trigger wording anywhere in os-vault), positives are 1/19 across both tiers while negatives are 18/18 clean — and the dominant failure shape is not "no persistence" but mis-routing to Claude Code's built-in auto-memory instead of the vault at L1; L2/L3 mostly don't persist at all.
tags:
  - type/eval-results
  - domain/llm-evaluation
  - tool/os-vault
  - tool/claude-code
  - project/cc-os
scope: global
last_updated: 2026-07-06
date: 2026-07-06
related:
  - eval-methodology-ladder
  - running-autoresearch-skill-evals
  - os-adr-eval-b-wording-experiment-hypotheses
  - os-adr-eval-c-frozen-grid-results
source: cc-os
---

# os-vault write eval — untuned baseline grid (2026-07-06)

## Results Grid/Threshold

**Passing criterion:** positives — unprompted vault write with contract-conforming
frontmatter (axis a: written or offered; axis b: mechanical frontmatter conformance);
negatives — no vault write (the sole fail line). Run-set × {sonnet, haiku} × 3 reps + 1
counted sonnet canary rep on P1 (37 counted reps total, zero harness errors, all rows
verified against expected rep counts).

| Cell | sonnet | haiku | Dominant behavior |
|---|---|---|---|
| P1-L1 explicit cue (Finch 500-cap) | 1/4 (canary only) | 0/3 | Persists EVERY rep — but to auto-memory (`~/.claude/projects/<slug>/memory/`), not the vault |
| P2-L2 no cue (Finch expires_in) | 0/3 | 0/3 | Fixes the code; no persistence anywhere |
| P3-L3 conceptual (Acme convention) | 0/3 | 0/3 | sonnet 1/3 wrote auto-memory; otherwise nothing |
| N1-L1 explicit cue, ephemeral | 3/3 | 3/3 | Status written to project file (`project-write:yes`), vault untouched |
| N2-L2 project-local quirk | 3/3 | 3/3 | Clean fix, no vault write |
| N3-L3 repo-recorded (ADR 0002) | 3/3 | 3/3 | Complies with the ADR, no vault duplicate |

**Summary:** positives 1/19 (the one pass: sonnet canary P1, which wrote a fully conforming
`reference/finch-api-page-size-silent-cap.md` — proof the ceiling exists); negatives 18/18
with zero over-trigger at any level on either tier. The measured gap is real and one-sided:
under-triggering plus destination mis-routing, no restraint problem.

## Measurement Setup

**Hypotheses / Scenarios Tested** — Ambiguity ladder L1 explicit-cue → L2 moderate → L3
conceptual, paired positive/negative per level (run-set: Finch API facts + Acme client
convention vs ephemeral status / project-local quirk / repo-recorded ADR). Reserve set
(chartkit + Globex + SFTP ADR) authored upfront, frozen, never read informally. Harness:
`cc-os/plugins/os-vault/eval/` (README documents scoring); TSV:
`eval/results/2026-07-06-baseline-grid.tsv`.

**Fixture and Sampling** — New `reportgen` Ruby fixture (Finch API reports CLI, 3-ADR
history via os-adr's own CLIs, deliberately plain CLAUDE.md with zero trigger wording) +
isolated sandbox vault (frozen copy of real vault-conventions.md + 4 topically-disjoint
seeded notes). Headless-only `claude -p` per rep with `OS_VAULT_PATH`/`OS_VAULT_SKIP_REBUILD`
isolation (verified: real vault untouched across all 37 reps; a canary transcript shows the
model writing into the sandbox vault path). 3 reps/cell + counted canary.

**Experimental Control (Frozen Surfaces)** — This is the pre-tuning baseline: os-vault
carried NO trigger-conditioned wording anywhere (WS2 defect 2 deliberately left in place).
Checker, fixtures, scenarios, judge rubric frozen. The only pre-baseline os-vault changes
were the WS2-sanctioned contract fix (write SKILL.md defers to vault-conventions.md) and the
isolation seam (OS_VAULT_PATH override + "Vault location" skill section).

## Validity and Limitations

**How to Interpret These Results** — Held-out baseline, nothing tuned against it yet; the
run-set remains the measurement set until a wording loop starts. The headline finding is the
**auto-memory competition channel**: on every L1 rep (both tiers) the model recognized the
knowledge as durable and persisted it — into Claude Code's built-in per-project auto-memory,
narrating it as "cross-repo memory" — so the trigger-recognition capability exists at L1 and
the failure is destination routing. (The user's global `~/.claude/CLAUDE.md` memory-routing
section loads in these sandbox sessions exactly as in production, so this competition is
production-faithful, not an artifact.) At L2/L3 the model mostly doesn't persist at all —
that part is a genuine trigger gap. P1 sonnet flipped between canary (vault) and grid
(auto-memory ×3): treat single-rep vault hits as variance, not capability proof.

**Weaknesses of This Eval (Its Ladder Level)** — Single fixture/domain for the run-set;
offer-detection judge never fired live (every positive either wrote somewhere or stayed
silent — the judge path is only self-test-validated so far); auto-memory routing is scored
only via the informational reasons trail, not a dedicated axis; no measurement of the
`/os-vault:write` skill when explicitly invoked (that's an Eval-A-shaped question, out of
scope here).

## Deployment and Evolution

**Good-Enough Gate** — Not applicable yet; this grid establishes the gap the WS2 wording
loop must close. Negatives at 18/18 mean restraint needs no work — wording iteration should
optimize trigger + routing only, and any future negative regression is a hard stop.

**Hardening Path / Next Measurement** — Per `ws2-os-vault-write-eval.md` step 4: an
`/autoresearch` wording loop (checker/fixtures/scenarios/rubric frozen; surfaces = write
SKILL.md description/body, an os-vault SessionStart usage note, possibly a trigger-phrased
CLAUDE.md section mirroring os-adr's). Two distinct wording jobs, per the axis-level
reading: (1) trigger at L2/L3, (2) route to the VAULT over the harness's built-in
auto-memory at L1 — wording that only says "remember this" will keep losing to auto-memory;
it must name the vault as the destination for evergreen cross-project knowledge. The moment
the loop starts, this run-set is training-set; the frozen reserve
(chartkit/Globex/delivery domain) becomes the measurement set.

## Related

- [[eval-methodology-ladder]] — ladder design + reserve discipline this harness follows
- [[running-autoresearch-skill-evals]] — loop discipline for the wording iteration ahead
- [[os-adr-eval-c-frozen-grid-results]] — the sibling discrimination eval whose shape this reuses