diff --git a/docs/PLUGIN-PHILOSOPHY.md b/docs/PLUGIN-PHILOSOPHY.md
index 9a9a2207e..cc6ec567a 100644
--- a/docs/PLUGIN-PHILOSOPHY.md
+++ b/docs/PLUGIN-PHILOSOPHY.md
@@ -569,6 +569,30 @@ the session default model changes):
 | Mechanical prep, one tier down | Sonnet 5 |
 | Bulk mechanical sweeps | Haiku 4.5 |
 
+That ladder is a cost ordering, and one capability does not travel down it: **interleaved thinking —
+a thinking block between tool calls rather than only before the first and after the last.** Claude Code
+models it per model, as the `interleaved_thinking` capability value
+([model config: customize pinned model display and capabilities](https://code.claude.com/docs/en/model-config#customize-pinned-model-display-and-capabilities),
+verified 2026-08-03; a pinned model's unlisted capabilities are disabled). The per-model roster is
+upstream-owned — resolve it at
+[thinking: interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking),
+which today states that interleaving is automatic on every model supporting adaptive thinking with
+no beta header, and that Claude Haiku 4.5 does not support it (verified 2026-08-03; recheck trigger:
+a new Haiku generation reaches GA, or that page's per-model sentence changes).
+
+The dispatch consequence, phrased as capability rather than family name so it survives an alias
+moving under it: **require interleaving only where extended reasoning between tool results is
+load-bearing — a mid-sweep judgement that has to change what gets called next. A task that chains
+calls, or that reasons over its results at the end, does not need it.** The boundary is much
+narrower than the capability's name suggests, and the same page draws it: "Consecutive tool calls do
+not require interleaved thinking. Claude can chain tool calls with or without interleaved thinking;
+interleaving changes where thinking blocks appear between tool calls, not whether tool calls can
+chain." What the capability adds is a thinking block at that seam, so what its absence removes is
+deliberation *at that point* — not the tool result from context, and not the ability to act on it.
+So the bottom tier row stands for bulk mechanical sweeps and for straightforward triage or research
+passes that decide at the end; the case it does not cover is a fan-out whose worth is deliberating
+partway through, where the next call must change because of what the last one returned.
+
 The **dispatch-seam** tier enforcement is structural at two binding sites:
 `plugins/implementation/agents/implementer.md` and
 `plugins/implementation/agents/phase-verifier.md` (both bind the loop-lane convention's strong-tier
@@ -589,6 +613,15 @@ support falls back to the highest supported level at or below it
 verified 2026-07-29). The ladder itself — level names, per-model availability, per-model defaults —
 is upstream-owned: resolve it from the model-config page at decision time, never from this document.
 
+What a pin actually buys is bounded by how allocation works: thinking is adaptive, so the model
+"evaluates each request and decides for itself whether to think and how much", and the caller sets
+an intent and optionally the effort while the model "allocates reasoning where it judges reasoning
+will help" ([steering thinking](https://platform.claude.com/docs/en/build-with-claude/thinking-steering-and-cost),
+verified 2026-08-03). A lane pin is therefore a posture, never a switch — a lane pinned `low` still
+thinks where the model judges thinking earns its cost, and a turn carrying no thinking is that
+mechanism working rather than a pin misfiring. Authoring conformance follows the posture: pin the
+lane, then let allocation vary per request instead of writing prose that tries to force it uniform.
+
 Lane rules, dated 2026-07-29 (recheck trigger: a model change on any pinned lane, or the
 model-config effort table changes — the effort scale is calibrated per model, so the same level
 name is not the same underlying value across models):
@@ -619,13 +652,37 @@ name is not the same underlying value across models):
   relatively small quality gains and can lead to overthinking. A pin above `high` (e.g. `xhigh`)
   is a deliberate per-lane choice grounded in the target model's own recommended-levels guidance,
   never a reflex.
-- **Shallow output from a pinned-`low` lane raises the lane's effort** rather than prompting
-  around it; only a lane that must stay `low` for latency gets upstream's targeted steering
-  guidance instead.
+- **Effort is the first lever in either direction; steering prose is the second.** Upstream states
+  the order plainly — set the effort level matching the lane's workload, then "add prompt guidance
+  only if Claude's triggering still doesn't match your needs at that level" — and gives the
+  rationale that lowering effort "is usually the better first lever, since it is a calibrated
+  control rather than a wording-sensitive instruction"
+  ([steering thinking: steering how often Claude thinks](https://platform.claude.com/docs/en/build-with-claude/thinking-steering-and-cost#steering-how-often-claude-thinks),
+  verified 2026-08-03). Both directions: shallow output from a pinned-`low` lane raises the lane's
+  effort rather than prompting around it, and a lane thinking more than the work needs lowers the
+  pin before any prose telling the model to think less — upstream states that reduce direction
+  outright and warns it "may reduce quality on tasks that benefit from reasoning". A lane that must
+  hold its level for latency is the one case that reaches for steering prose first; it then owes
+  the measurement upstream asks for — a representative sample run with and without the guidance,
+  compared on trigger rate, output tokens, latency, and quality — because steering effectiveness is
+  wording-sensitive in a way a level is not. Authoring a lane's prose against its own pin, in
+  either direction, is the inversion this rule exists to catch.
 - **Cache caveat**: changing effort between requests invalidates cached prompt prefixes, so a
   skill pin firing mid-session is expected to cost the main conversation's cache (harness-side
   request assembly unconfirmed), while a subagent pin is scoped to the subagent's own requests —
-  treat skill-lane pins as cache-costly in cost-sensitive loops.
+  treat skill-lane pins as cache-costly in cost-sensitive loops. State the outcome and not the
+  mechanism: the platform page and the harness page agree that an effort change forces a full
+  re-read but describe *why* differently, so an explanation that picks one is asserting more than
+  either source supports. Two corollaries follow. Setting a lane's effort explicitly to the model's
+  own default is a no-op that "does not break the cache", so a pin that merely documents the
+  default costs nothing. And **per-message steering is the cache-safe escape hatch** — guidance
+  appended to the newest user message "leaves earlier cache breakpoints intact, where a
+  configuration or effort change does not", which is what makes a skill's invocation-time
+  instructions cheaper than a mid-session pin. The convention that falls out, and the reason a lane
+  pin is a design-time choice rather than a per-task one: pick the level once and keep it, steer
+  per message when one turn needs more or less, and move the configuration only at natural breaks
+  between tasks ([steering thinking: prompt caching](https://platform.claude.com/docs/en/build-with-claude/thinking-steering-and-cost#prompt-caching),
+  verified 2026-08-03).
 
 Session-level effort is the consumer's own knob, out of plugin scope: `low` through `xhigh`
 persist via the `effortLevel` setting, while `max` and `ultracode` are session-only — `max` is
diff --git a/plugins/playbooks/.claude-plugin/plugin.json b/plugins/playbooks/.claude-plugin/plugin.json
index ee39ec28f..01d861942 100644
--- a/plugins/playbooks/.claude-plugin/plugin.json
+++ b/plugins/playbooks/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "playbooks",
-  "version": "0.6.2",
+  "version": "0.6.3",
   "description": "Doctrine and knowledge playbooks as on-demand skills, plus a maintainer-facing update skill. boris — Boris Cherny's Claude Code workflow tips (howborisusesclaudecode.com); skill-authoring — Anthropic's internal skill-authoring playbook; fable-5 — Claude Fable 5's operating doctrine (self-authored, no upstream). The boris and skill-authoring packs vendor a verbatim upstream baseline; /playbooks:update drift-checks and syncs those baselines centrally (maintainers).",
   "author": {
     "name": "Melodic Software",
diff --git a/plugins/playbooks/CHANGELOG.md b/plugins/playbooks/CHANGELOG.md
index c14626e42..b41b43437 100644
--- a/plugins/playbooks/CHANGELOG.md
+++ b/plugins/playbooks/CHANGELOG.md
@@ -4,6 +4,32 @@ All notable changes to the `playbooks` plugin are recorded here. The `version` i
 `.claude-plugin/plugin.json` is the delivery vehicle — a consumer receives a change
 only after that version increases.
 
+## [0.6.3]
+
+### Added
+
+- **`fable-5` calibration gains the product-surface scope rule.**
+  `skills/fable-5/context/calibration.md` adds "A claim's product surface travels with it": a
+  behavioral claim about Claude is a fact about the surface documenting it, and it transfers to the
+  surface the session runs on only after a per-claim check — never on vendor authority alone. The
+  rule is scoped to CROSS-surface transfer, which is the row's actual thesis: docs for the running
+  surface clear the check where they stand, so Claude Code's own docs read inside Claude Code are
+  not downgraded. A dated archive entry is scoped to its date on top of that. Two worked
+  divergences carry it, both genuine published text from Anthropic's claude.ai system prompts and
+  both false read as facts about this harness — "Claude does not retain information across chats"
+  (Claude Opus 4.1 entry, dated August 5 2025) against Claude Code's two documented cross-session
+  mechanisms, CLAUDE.md files and auto memory; and "Claude cannot open URLs, links, or videos"
+  (Claude Sonnet 3.5 entry, dated November 22 2024) against the documented `WebFetch` tool. Both are
+  stamped to their entry rather than stated in the present tense, because **neither sentence
+  survives in a current entry** — wrong-surface and stale-entry are independent errors, and the
+  staleness is the rule's second half rather than a defect in the example. Verified 2026-08-03
+  against [published system prompts](https://platform.claude.com/docs/en/release-notes/system-prompts),
+  [memory](https://code.claude.com/docs/en/memory), and
+  [tools reference](https://code.claude.com/docs/en/tools-reference); recheck trigger: a new dated
+  entry restores or reverses either sentence, or Claude Code's memory or tool surface changes.
+  `skills/fable-5/SKILL.md` carries the distilled line under core doctrine, "Ground truth and
+  checking — calibration", per the chapter/core-doctrine pairing the rest of that file follows.
+
 ## [0.6.2]
 
 ### Fixed
diff --git a/plugins/playbooks/skills/fable-5/SKILL.md b/plugins/playbooks/skills/fable-5/SKILL.md
index 161207fec..cae46e37f 100644
--- a/plugins/playbooks/skills/fable-5/SKILL.md
+++ b/plugins/playbooks/skills/fable-5/SKILL.md
@@ -44,6 +44,7 @@ The distillation of every chapter, grouped in operating-loop order. Each line is
 - Trust no count or zero-hit result until you have ruled out output caps and validated the probe against a known-present example.
 - Pre-register a prediction before any action with observable output — no expectation means surprise is undetectable.
 - Settled means settled: reopen a session-verified, untouched fact only on contradicting evidence, never data-free doubt.
+- A behavioral claim about Claude is a fact about the surface documenting it, and it transfers to the surface you are running on only after a per-claim check — never on vendor authority alone, which is what makes a scope slip invisible. Docs for your own surface clear that check where they stand; a claim from another surface (consumer apps, the raw API) is a hypothesis until checked, and a dated archive entry is scoped to its date on top of that.
 
 ### Thinking — reasoning-moves
 
diff --git a/plugins/playbooks/skills/fable-5/context/calibration.md b/plugins/playbooks/skills/fable-5/context/calibration.md
index 7a778e2a4..a9312c4c2 100644
--- a/plugins/playbooks/skills/fable-5/context/calibration.md
+++ b/plugins/playbooks/skills/fable-5/context/calibration.md
@@ -27,6 +27,21 @@ Rank every belief by its distance from observation: direct observation this sess
 > Weak: "The test passed, so the parser works, so the import pipeline works, so the report is correct." — the final claim stands three steps from evidence.
 > Strong: open the actual report output once; the claim is now zero steps from evidence.
 
+## A claim's product surface travels with it
+
+Same-vendor documentation is the easiest scope error to make, because it never feels like an inference: you read an authoritative sentence about Claude and it lands as a fact about the Claude you are. It is a fact about the surface that sentence documents. Consumer claude.ai and mobile, the raw API, and this harness are different products with different tools, memory, and system prompts; a claim crosses between them only after a per-claim check against the target surface's own docs.
+
+- TRIGGER: about to act on a behavioral claim about Claude that you did not observe on this surface this session — official vendor documentation included, and especially then, since its authority is what makes the scope slip invisible.
+- RULE: name the surface a claim documents before using it. Same surface as the one you are running on — Claude Code's own docs, here — and naming it IS the check: it clears at that point and nothing further is owed. A different surface makes the claim a hypothesis about yours, one inference step out, and settling it costs a single lookup in the target surface's own docs.
+- RULE: a dated archive is scoped to its date as well as its surface. A published prompt entry describes one model on one day; a sentence's later absence is not a correction you can read off the page.
+
+Two worked divergences, both genuine published text from Anthropic's claude.ai system prompts, both false about this harness, and both already superseded (verified 2026-08-03 against the [published system prompts](https://platform.claude.com/docs/en/release-notes/system-prompts), [Claude Code memory](https://code.claude.com/docs/en/memory), and the [tools reference](https://code.claude.com/docs/en/tools-reference)):
+
+- "Claude does not retain information across chats" — Claude Opus 4.1 entry, dated August 5 2025. Here, two documented mechanisms carry knowledge across sessions: CLAUDE.md files and auto memory.
+- "Claude cannot open URLs, links, or videos" — Claude Sonnet 3.5 entry, dated November 22 2024. Here, `WebFetch` is a documented tool.
+
+Neither sentence survives in a current entry, which makes wrong-surface and stale-entry independent errors: a reader who caught only the surface mismatch would still be quoting a retired prompt. Clear both before a vendor sentence becomes a premise.
+
 ## The check / skip decision
 
 Checking is an investment, not a virtue. Decide with the rules below. Already-settled exits first: a session-verified, untouched claim is evidence, not a claim needing a check — it leaves this matrix entirely (see "Settled means settled"). Among the rest, precedence: silent-failure mandate, then the gating-and-expensive test (its ≤2-call cost cap lives inside it), then the loud-fast-free skip, then DEFAULT.