docs: gemma4:26b as persistent-correspondence agent

Single-shot test against real Andy inbound + CONTEXT.md slice.

Findings: gemma4 handles state bookkeeping well (correctly diffs
Pending, honors hard rules like rejected-analogy avoidance, uses
agreed vocabulary). Fails on precision: hallucinated message ID,
invented Figure 1 axes it had no access to, drifted off voice
register without few-shot examples.

Verdict: viable for low-stakes social correspondence + first-pass
triage; disqualified from high-stakes drafting where exact IDs
or artifact references must round-trip. Hybrid pattern proposed
(gemma4 for bookkeeping, Claude for drafting).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/persistent_correspondant.md

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+# Gemma 4 as a persistent-correspondence agent
+
+**Date:** 2026-04-18
+**Model:** `gemma4:26b` via mcp-gemma4 (steel141 Ollama)
+**Test fixture:** Real inbound message from Andy Freiberg (Apr 19, 2026), real CONTEXT.md slice from `~/bin/spaceflight/andy/`
+**Question:** Could gemma4 run an Andy-style persistent correspondence (drafting + state management)?
+
+## TL;DR
+
+**Partial yes, supervised. Full no, unsupervised.**
+
+Gemma4 handles the **bookkeeping** half of persistent correspondence well — state diffs, pending-list maintenance, summarizing what's open. It fails the **drafting** half whenever precision matters: it hallucinates message IDs, invents figure content it can't see, and drifts off the established voice register without explicit examples.
+
+For a low-stakes social correspondence (Discord chat with a friend, no IDs needed) gemma4 would be fine. For the Andy correspondence specifically — high-stakes scientific writing with manuscript references, figure specs, and a senior physician collaborator — it would need either Claude as a quality gate or a tool-using setup with retrieval over actual artifacts.
+
+## Test setup
+
+Single-shot test via `mcp__gemma4__ask_gemma4`:
+
+- **System prompt:** Set Claude's persona, voice rules, draft→review→send convention.
+- **User prompt:** Slice of CONTEXT.md (Pending section, vocabulary bridge, conventions agreed) + the verbatim Apr 19 inbound from Andy + two-part task (state diff + draft reply).
+- **Settings:** `temperature=0.5`, `num_predict=2000`, default `num_ctx=8192`.
+
+Total input fit comfortably in the 8K context. No tool calls. No retrieval — gemma4 worked from prompt content alone, the same constraint a real correspondence run would put on it (modulo whatever gets loaded into context per turn).
+
+## Results
+
+### What gemma4 got RIGHT
+
+| Capability | Evidence |
+|------------|----------|
+| State bookkeeping | Correctly removed inbound from "Waiting on us", added new pending action items (figure work), kept Cambridge-editors carryover. The reasoning chain is sound. |
+| Honored hard rules | Did NOT resurrect the rejected exaptation analogy. The "don't do X" instruction in the system prompt held. |
+| Used agreed vocabulary | Used "diel," "conspecific," etc. correctly. Did not invent terminology. |
+| Reply structure | Addressed all four asks in order. Decisions acknowledged tersely; action items as concrete bullets. Skeleton matches Claude's style. |
+| Caught the carryover | Asked Andy for the Cambridge editor list — correctly flagged the open item that's been pending since Apr 17. |
+
+### What gemma4 got WRONG (load-bearing failures)
+
+| Failure | What it produced | What was correct | Cost |
+|---------|------------------|------------------|------|
+| **Hallucinated message ID** | `19da34ng...` | `19da34bc8e6ec51a` | Disqualifying. Cannot thread/reply on the actual platform. |
+| **Hallucinated figure content** | Figure 1 axes = "trade-off between metabolic cost and temporal opportunity" | Real axes = Tinbergen 4Q grid: Static/Dynamic × Proximate/Ultimate | Andy would catch on first read; we lose credibility. |
+| **Vague figure plans** | "Integrate molecular signaling pathways into Figure 3" | Real plan: per-population specifics — Pachón hypocretin, Tinaja/Molino distinct QTLs, shared attenuated per1 | Reply reads as a hand-wave; no actual content. |
+| **Wrong voice register** | "Hi Andy" / "Best, Claude" / no AI disclaimer footer | "Dear Dr. Freiberg" / "Yours, Claude" / explicit AI-content disclaimer | Recognizable as off-brand. Disclaimer omission is a policy violation. |
+| **Wrong CONTEXT.md schema** | Created a "Resolved" section | Schema has Pending / Sent / Received only | Minor — extrapolation, not invention. |
+
+### Why these failures happened
+
+Two distinct failure modes, neither fixable by prompt engineering alone:
+
+1. **No access to the actual artifacts.** The figures live in `~/bin/spaceflight/andy/manuscript/figures/`. Gemma4 was not given them; it had no way to know what Figure 1 actually contains. Faced with a "describe what you'll change" task, it generated plausible-but-fictional content. This is the **classic hallucination-under-constraint failure mode**: the model would rather make something up than refuse.
+
+2. **No few-shot examples of the target voice.** The system prompt described the voice ("Maintain Claude's voice") but didn't show it. Gemma4 defaulted to its trained-in casual register ("Hi Andy" / "Best, Claude"). A few-shot prompt with one or two real Claude-to-Andy letters would likely close most of this gap; the underlying capability is there.
+
+## Where gemma4 fits
+
+### Plausible roles
+
+- **Low-stakes social correspondence.** Discord/Matrix chat with a friend. No precise IDs to preserve. Tolerance for vague replies is high.
+- **First-pass triage.** Given inbound + CONTEXT.md, produce the state diff and a draft outline. Claude (or a human) reviews before send. This is the highest-value role — bookkeeping is the bulk of the work and it's where gemma4 is strongest.
+- **Scheduled status checks.** "Anything new from Alice this week?" → summary. Read-only, no draft, no IDs to corrupt.
+- **CONTEXT.md maintenance.** After a send, ask gemma4 to update the Sent table and Pending list from the message header alone.
+
+### Disqualifying contexts
+
+- **The Andy correspondence specifically.** Too many precise references that gemma4 would invent.
+- **Anything requiring exact ID round-tripping.** Gmail message IDs, git SHAs, ticket numbers, citation keys, DOIs.
+- **Anything where the model needs to reference attachments it can't read.** Figures, manuscripts, reviewer comments. It will hallucinate content.
+- **Long-thread continuity tasks** where the conversation history exceeds 8K context and you need to reason over the full archive.
+
+## Practical hybrid architecture
+
+The persistent-correspondence template at `~/bin/persistent-correspondence/` doesn't need to change to support a hybrid setup. The routing decision lives in each contact's `CONTEXT.md` "workflow" section:
+
+```
+## Workflow
+
+1. Inbound trigger → gemma4 produces CONTEXT.md state diff + draft outline.
+2. Claude reviews the diff, applies it. For high-stakes contacts, Claude
+   rewrites the draft with full artifact context. For low-stakes contacts,
+   Seth reviews gemma4's draft directly.
+3. Send via the platform adapter. Gemma4 updates the Sent table from the
+   send confirmation.
+```
+
+This pattern lets gemma4 carry the volume work (state maintenance) without putting it in the critical path on accuracy-sensitive output.
+
+## What this test did NOT cover
+
+- **Multi-turn context retention.** Single-shot only. Real correspondence is many turns.
+- **Tool calling.** Gemma4 supports it (`tools` parameter on the MCP). A retrieval-augmented gemma4 that can `read_attachment(filename)` would likely close the figure-hallucination gap. Not tested here.
+- **Few-shot voice priming.** No example letters in the prompt. Voice scores would likely improve significantly with 1-2 in-context examples.
+- **Smaller/larger Gemma 4 variants.** Only `gemma4:26b` tested. The 31b might do better on precision; the 8b would almost certainly do worse.
+- **Other models.** No comparison against gpt-oss, qwen, etc. for the same task.
+
+## Reproducing this test
+
+The full prompt + system message used is in the conversation transcript that produced this report. Key prompt-engineering choices to replicate:
+
+- Include actual CONTEXT.md content (not a paraphrase) so the schema is concrete.
+- Include the verbatim inbound message, not a summary.
+- Split the task: state diff first (cheap, structural), draft second (expensive, precision-sensitive). Lets you grade independently.
+- Use temperature 0.3-0.5 for correspondence work — low enough to suppress invented content, high enough to keep the prose natural.
+
+## See also
+
+- `~/bin/persistent-correspondence/` — the template abstracted from the Andy correspondence
+- `~/bin/spaceflight/andy/CONTEXT.md` — the reference implementation this test was drawn from
+- `~/bin/gemma4-research/README.md` — overall Gemma 4 reference and gotchas