docs(brain): add agent-consumer brain-MCP intent analysis

Agent-consumer column of the two-part brain intent↔interface study.
Reconstructs the knowledge-act behind every brain MCP call in the
Claude Code agent transcripts on koala (the only corpus with brain
calls; brain/sessions and agentsquad eval logs carry none).

46 distinct knowledge-acts, 37% interface mismatch, 0% intent_unclear.
Headline gap: no update/supersede verb → agents blind re-write same
slug (5x); no read-after-write → lexical re-query of own note (4x);
lexical-only reads → semantic-as-keyword-stuffing chains (3x);
brain_answer hedged with parallel brain_query.

Canonical schema brain-intent-extraction.md absent on host; vocab
reconstructed, every row tagged schema_source=reconstructed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

brain/sessions/analysis/agent-intent-column.md

@@ -0,0 +1,148 @@
+# Agent-Consumer Brain Intent Analysis — koala column
+
+**Consumer:** `autonomous_agent` (all rows). **Host:** koala. **Date:** 2026-06-15.
+**Raw rows:** `agent-intent-column.jsonl` (46 real knowledge-acts + 1 excluded false-positive).
+
+## Caveat — canonical schema not on this host
+
+The shared closed-vocabulary file `brain-intent-extraction.md` **does not exist on
+koala** — the only reference to it is inside *this task's own prompt*. The intent
+vocabulary below was **reconstructed** from the prompt's framing + `brain/schema.md`.
+Every row carries `schema_source: reconstructed`. If the canonical vocab differs,
+re-map the `intent` field; the `intent_tool_match` / `workaround` / `observed_friction`
+evidence stands regardless of label names.
+
+**Reconstructed closed vocab:** `semantic_retrieval`, `lexical_lookup`,
+`check_prior_art`, `synthesized_answer`, `store_new_knowledge`, `update_or_supersede`,
+`ingest_raw_source`, `verify_write_landed`, `discover_capability`, `intent_unclear`.
+
+## Corpus
+
+- `~/.claude/projects/*/*.jsonl` — Claude Code agent transcripts (98 files). **The only
+  source with brain calls.**
+- `brain/sessions/*.jsonl` — empty (only `.gitkeep`).
+- `agentsquad docs/eval/*.jsonl` — code-review eval results, **not** brain calls.
+- No separate Crush session logs on this host.
+- **Zero** brain calls were human-typed. Every brain act is agent-initiated (the
+  CLAUDE.md "query as reflex / close-the-loop write" behaviour), so all qualify as
+  `autonomous_agent`. The human gave the top-level task; the agent chose every brain act.
+
+## 1. Intent histogram, split by `intent_tool_match`
+
+| intent | match | mismatch | partial | total |
+|---|---|---|---|---|
+| check_prior_art | 10 | 0 | 0 | 10 |
+| store_new_knowledge | 14 | 1 | 0 | 15 |
+| update_or_supersede | 0 | 5 | 0 | 5 |
+| synthesized_answer | 2 | 2 | 1 | 5 |
+| verify_write_landed | 0 | 4 | 0 | 4 |
+| semantic_retrieval | 0 | 3 | 0 | 3 |
+| ingest_raw_source | 2 | 0 | 0 | 2 |
+| discover_capability | 0 | 2 | 0 | 2 |
+| **total** | **28** | **17** | **1** | **46** |
+
+> Batch note: several rows collapse a same-second fan-out of identical-intent calls
+> (a10=3, a11=4, a14=5, a33=3, a34=3, a35=3). Call-level the corpus is ~62 brain calls;
+> the table counts the 46 distinct knowledge-acts. Frequency is deliberately *not* the
+> point — the mismatch column is.
+
+**37% of agent knowledge-acts (17/46) are interface mismatches.** Every mismatch falls
+into one of four intents: `update_or_supersede`, `verify_write_landed`,
+`semantic_retrieval`, `discover_capability` — plus one `store` that had to use HTTP.
+
+## 2. Mismatch list, grouped by intent (primary deliverable)
+
+### update_or_supersede → re-write same slug (5/5 mismatch) — HIGHEST VALUE
+There is **no update / patch / append / supersede verb**. When an agent improves a note
+it already wrote, the only move is to call `brain_write`/`brain_ingest` **again with the
+same filename/source** and hope the index replaces rather than duplicates. Observed:
+
+| slug | 1st write | 2nd write | gap | what changed |
+|---|---|---|---|---|
+| `tapir-rls-identity-bootstrapping` (ingest) | 14:00:59 | 14:02:08 | 69s | condensed body |
+| `homelab-security-chains-not-bugs.md` | 09:28:22 | 10:32:49 | 64m | new worked example |
+| `webfetch-readme-when-image-or-flag-uncertain.md` | 18:31:23 | 18:34:23 | 3m | near-identical (retry) |
+| `gitea-mcp-per-repo-tools-404-and-rest-fallback` | 05:57:37 | 05:57:55 | 18s | content tweak |
+| `cannot-move-ingress-host-across-namespaces-flux-dryrun` | 13:59:50 | 14:00:13 | 23s | content tweak |
+
+Sub-30s gaps (3 of 5) read as "I wanted to edit but can only overwrite." The agent has
+no way to know whether the second write deduped or created a contradictory v2 — opacity
+the brain's own design principle (`mcp-tool-design-get-needs-list-partner.md`, written
+*by one of these very agents*) would flag: every `_write` needs a `_get`/`_update` partner.
+
+### verify_write_landed → lexical re-query (4/4 mismatch)
+No read-after-write / get-by-id confirmation. After every substantive write, agents
+re-query lexically to check the note is retrievable — and *reformulate the keywords*
+because they can't predict what BM25 indexed:
+- `exit-255` lesson: query `exit 255 unknown reason restart loop diagnosis` → write →
+  query `exit 255 unknown SIGKILL containerd`.
+- `extension-version-lags`: query `extension build pinned version...pgvector` → write →
+  query `pgvector postgres extension version compile error bump`.
+- `webfetch-readme`: write → write → query stuffed with the note's own section headings.
+
+### semantic_retrieval → BM25 keyword-stuffing (3/3 mismatch)
+Agent knows the *meaning* but not the *indexed words*, so it brute-forces phrasings of
+one need against a lexical tool:
+- **4-step chain on one Go bug:** `bytes.Buffer Bytes Reset aliasing slice sharing` →
+  `go buffer reuse map backing array bug` → (write) → `go map values all show same
+  content after loop` → `bytes.Buffer Bytes returns same data every iteration`. Symptom
+  and cause both known; no single lexical query bridges them.
+- Natural-language questions (`how to enable prometheus metrics on litellm proxy
+  callback`, `moved compose stack to new directory volumes disappeared empty`) shoved
+  into `brain_query`.
+
+### synthesized_answer → fall back to / hedge with brain_query (2 mismatch + 1 partial)
+`brain_answer` is frequently **not trusted as terminal**:
+- **Strongest signal:** 3× `brain_answer` at 15:08 (compose volumes / pi rebuild time /
+  litellm ModuleNotFound) → 3× `brain_query` at 15:09 on the *same three topics*. The
+  agent asked the synthesizer, was unsatisfied, and immediately re-ran raw search.
+- Dex→Authentik: `brain_query` and `brain_answer` fired **8s apart on one question** —
+  the agent pays both interfaces because it can't predict which returns usable knowledge.
+- (Counter-examples exist: `brain_answer` for episodic recall — "what happened with the
+  litellm migration on 2026-05-16?" — was consumed and not re-queried. So `answer`
+  works for *episodic/temporal* recall, fails for *how-do-I / does-X-hold* reasoning.)
+
+### discover_capability + store-via-HTTP (3 mismatch)
+brain tools are **not ambient** — they are deferred and must be `ToolSearch`-loaded each
+session. Agents fumble the discovery (`ToolSearch 'brain knowledge memory'` →
+`'brain'` → `'brain ingestion knowledge wiki'`) and, when MCP load/auth fails, drop to
+**raw `curl` against `brain-mcp` / hand-built `/tmp/brain_entry.json`**. One agent even
+`ToolSearch`-ed an `authenticate` tool, then abandoned MCP for the HTTP bodge — matching
+the known "brain/op MCP auth lapses too often" footgun.
+
+### Write-interface / layer schema confusion (cross-cutting)
+`brain_write` was called with **three different param shapes** in the same corpus:
+`{filename, type:"lesson", content}`, `{filename, content}` (no type), and
+`{wing:"tapir", hall:"failures", filename, content}` — plus `brain_ingest {source,
+content}`. Agents are unsure which verb and which layer (flat slug vs `wing`/`hall`
+knowledge routing vs raw ingest) a given knowledge-act maps to. This is the
+`knowledge/ vs wiki/` confusion expressed at the parameter level.
+
+## 3. `intent_unclear` rate
+
+**0 / 46 genuine brain acts (0%).** Agent intent is unusually legible because these are
+Claude Code transcripts: the surrounding task, the query/filename strings, and the
+write content all disambiguate. One row (`a47`) was tagged `intent_unclear` and
+**excluded** — its `brain_` substring was inside a git commit message, not a brain call.
+Example of the only ambiguity that arose: a `brain_answer` on "gitea MCP not working...
+how to authenticate" followed by an unrelated query — can't tell if the answer satisfied
+or was abandoned (`partial`, row a28).
+
+## 4. The single biggest intent↔interface gap
+
+**The brain offers one write verb and one lexical read verb, but autonomous agents
+perform four distinct knowledge-acts against them — and three of the four have no fitting
+interface.** The deepest gap is the **missing update/supersede path**: agents close every
+task by writing a lesson (the CLAUDE.md ritual), routinely improve it minutes-to-an-hour
+later, and — having no edit primitive — re-write the same slug blind, unable to tell
+whether they corrected the entry or forked a contradiction into the index. This compounds
+with the lexical-only read side: because there is no `get-by-id` or semantic retrieval,
+agents can't even reliably *find their own just-written note* to check it, so they
+keyword-stuff reformulated queries and hedge `brain_answer` with parallel `brain_query`.
+The interface is built for *append-and-keyword-search*; the agents are trying to
+*curate a living, deduplicated knowledge base*, and the seam between those two shows up
+as the 5 blind re-writes, 4 read-after-write re-queries, and 3 semantic-as-lexical chains
+that dominate the mismatch column.
+
+---
+*Evidence-only per task scope — no redesign proposed.*