docs(tdd): fix ten defects the GREEN run found in the language references

The pressure test that #18 and #20 were waiting on. All six original gaps came
back ANSWERED with the lines quoted — and the run then found ten problems in
what I had written. The worst two are mine, not inherited.

**The Python exemplar was the evaluation task.** references/python.md
demonstrated `split_vat` — the exact function the test scenario asks for,
negative-amount case included. The run said so: "as a teaching example that's
over-fitted; as an evaluation it's a leak... this task can't answer it — the
reference handed over the finished artifact." So the run could not measure
whether the guidance transfers, only whether copying works. The exemplar is now
`parse_retry_after`, deliberately unrelated to anything in this estate, and it
states its own contract rather than requiring the reader to divide 12500 by 1.25
to discover it.

**mypy at RED pointed at the stub the same file forbids.** python.md taught that
a pytest ImportError is a legitimate red, then presented `mypy --strict` as a
matched pair without saying that mypy reports the same missing module — so
following both literally, the way to get mypy green at RED is to create the
module. Now stated: that error is the expected red; what must be fixed
immediately is a --strict violation inside the test file you just wrote.

The rest, each quoted in the run:

- The checklist contradicted itself two lines apart — "strike it deliberately"
  above, "Can't check all boxes? You skipped TDD" below. A struck box is by
  definition unchecked, so the Python path routed straight into "start over".
- `match=` was overclaimed as "free". It is `re.search`, so a message containing
  parens quietly matches almost anything; and it couples every error test to
  wording. The Go comparison was a strawman against `assert.Error` when
  `assert.ErrorIs` exists — the honest Python analogue is a custom exception
  type, with `match=` as the fallback.
- `pytest.approx` was listed as the soft-assert analogue. It solves float
  tolerance and has nothing to do with collecting failures; that is
  pytest-subtests or pytest-check, neither of which ships with pytest.
- The whole-shape assertion silently required value equality — on a plain class
  it compares identity and can never pass.
- "When Stuck" is a language-neutral table that prescribed `t.Helper()`.
- `__tracebackhide__` must be a local inside the helper body; at module level it
  does nothing, silently.

Refs #18, #20
Bump-Type: patch

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "skills",
   "description": "Mathias's engineering skills library, plus the hooks and MCP servers that make it enforceable: TDD, clean code, debugging, specs, discovery, CI, and secret hygiene.",
-  "version": "0.13.4",
+  "version": "0.15.0",
   "author": {
     "name": "Mathias",
     "url": "https://git.d-ma.be/mathias"

Taskfile.yml

@@ -114,7 +114,12 @@ tasks:
         #    session_id is its only required field, and nine skills omitted it.
         sh '{{.TASKFILE_DIR}}/bin/check-session-log' '{{.TASKFILE_DIR}}' || fail=1
 
-        # 6. Plugin manifest version must match the latest tag, or installers
+        # 6. Every skill says when it stops and hands back (#5). Skills whose
+        #    rule is not written yet are listed in bin/escalation-pending.txt,
+        #    which only shrinks.
+        sh '{{.TASKFILE_DIR}}/bin/check-escalation' '{{.TASKFILE_DIR}}' || fail=1
+
+        # 7. Plugin manifest version must match the latest tag, or installers
         #    never see the update (Claude Code gates updates on this field).
         if [ -f '{{.PLUGIN_MANIFEST}}' ]; then
           manifest_v=$(sed -n 's/.*"version"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/p' '{{.PLUGIN_MANIFEST}}' | head -1)

bin/check-escalation

@@ -0,0 +1,64 @@
+#!/bin/sh
+# check-escalation — every skill states when it stops and hands back.
+#
+# #5 decided this belongs in the body, not the frontmatter: no harness reads
+# frontmatter beyond name/description, so a `failure_criteria:` key would be a
+# guarantee nothing honours. The model reads the body.
+#
+# #37 then had to define which skills need one, and every obvious answer was
+# bad: a hardcoded list rots, sniffing the text for "does it write anything" is
+# unfalsifiable, and a frontmatter flag is the rejected option wearing a hat.
+#
+# So there is no acting set. EVERY skill answers the question. A read-only skill
+# answers it in one line — "read-only; findings are the output, nothing is
+# handed back" — which turns an absence into a claim someone can disagree with.
+#
+# bin/escalation-pending.txt is a ratchet for skills whose real rule has not
+# been written yet (a stop condition nobody thought about is not worth
+# enforcing). It is self-cleaning: a listed skill that HAS a section fails, so
+# the list cannot outlive its reason.
+#
+# Usage: check-escalation [checkout-root]
+
+set -u
+
+ROOT=${1:-$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)}
+PENDING="$ROOT/bin/escalation-pending.txt"
+fail=0
+
+listed() {
+  [ -f "$PENDING" ] || return 1
+  sed 's/#.*//' "$PENDING" | grep -qx "[[:space:]]*$1[[:space:]]*"
+}
+
+for dir in "$ROOT"/skills/*/; do
+  [ -f "$dir/SKILL.md" ] || continue
+  name=$(basename "$dir")
+
+  if grep -q '^## Escalation' "$dir/SKILL.md"; then
+    if listed "$name"; then
+      echo "ERROR: skills/$name has an Escalation section but is still in bin/escalation-pending.txt — remove it from the list" >&2
+      fail=1
+    fi
+    continue
+  fi
+
+  listed "$name" && continue
+  echo "ERROR: skills/$name has no '## Escalation' section — say when it stops and hands back, or say it never does" >&2
+  fail=1
+done
+
+# A pending entry for a skill that no longer exists is a stale exemption, and a
+# stale exemption is how a gate quietly stops covering something. Looped without
+# a pipe on purpose: a `while read` on the right of a pipe runs in a subshell,
+# so `fail=1` would be set in a process that exits before it is read.
+if [ -f "$PENDING" ]; then
+  entries=$(sed 's/#.*//' "$PENDING" | tr -d '[:blank:]' | grep -v '^$' || true)
+  for entry in $entries; do
+    [ -f "$ROOT/skills/$entry/SKILL.md" ] && continue
+    echo "ERROR: bin/escalation-pending.txt lists '$entry', which has no skills/$entry/SKILL.md" >&2
+    fail=1
+  done
+fi
+
+exit $fail

bin/escalation-pending.txt

@@ -0,0 +1,42 @@
+# Skills whose escalation rule has not been written yet (#37).
+#
+# This list only shrinks. A skill here is exempt from the '## Escalation'
+# requirement until someone writes its real stop conditions; a skill that HAS a
+# section and is still listed fails the gate, so the list cannot outlive its
+# reason.
+#
+# The ones already done were the advisory and read-only skills, where the honest
+# answer is a line. What is left is the acting set — skills that write files,
+# dispatch agents, touch credentials or move releases — and each of those needs
+# a rule someone thought about, not a rote paragraph. Per #19, one at a time.
+
+atdd
+dream
+experiment-spec
+feature-spec
+gitea-ci
+own-the-task
+planning
+playwright
+problem-analysis
+refactoring
+regulatory-risk-assessment
+secret-hygiene
+session-retrospective
+spec-driven-dev
+superpowers-brainstorming
+superpowers-dispatching-parallel-agents
+superpowers-executing-plans
+superpowers-finishing-a-development-branch
+superpowers-receiving-code-review
+superpowers-requesting-code-review
+superpowers-subagent-driven-development
+superpowers-using-git-worktrees
+superpowers-using-superpowers
+superpowers-verification-before-completion
+superpowers-writing-plans
+superpowers-writing-skills
+tdd
+trainer
+user-stories
+web-shot

skills/cad-babysit/SKILL.md

@@ -258,3 +258,13 @@ decide
 - `mathias/cad-atlas#11` renders the same `cad stuck` output as a pipeline overlay — read that
   instead of this skill's text output when a visual "where is everything stuck" view is wanted
   over working one row in depth.
+
+## Escalation
+
+Read-only by construction, and the Iron Laws above are the escalation rule: never close
+an issue, never dispatch, never write a label. Everything that is the operator's call
+leaves as a `DECISION NEEDED` block (question / options / recommendation / blocks).
+
+Stop and hand back when: the stuck queue is empty; a diagnosis needs a write you are not
+allowed to make; or two runs in a row produce the same finding, which means the finding
+is not being acted on and repeating it is noise.

skills/clean-code/SKILL.md

@@ -284,3 +284,11 @@ During refactoring:
 - `references/python-adaptation.md` — Python conventions: error chaining, dataclasses, the truthiness trap
 - Load `solid` skill for SOLID principles with Go examples
 - Load `refactoring` skill for systematic refactoring techniques
+
+## Escalation
+
+Advisory during the REFACTOR phase. Suggests; does not restructure behaviour.
+
+Stop and hand back when: the cleanup you are proposing changes behaviour. That is not
+refactoring, it is a change, and it needs its own failing test first — hand back to
+`tdd`.

skills/code-review/SKILL.md

@@ -285,3 +285,12 @@ treats `pass` as success, `fail` as failure, `skip` as neither.
 - Load `refactoring` skill when recommending fixes
 - Load `test-design` skill for reviewing test quality
 - Load `solid` skill for SOLID principle violations
+
+## Escalation
+
+Read-only analysis. Findings are the output; nothing is handed back mid-review.
+
+Stop and hand back when: the diff is large enough that a review would be a skim — say so
+and ask for it in parts, rather than producing confident coverage of a fraction of it; or
+the problem is structural rather than pointwise, in which case name it and hand off to
+`solid` or `refactoring` instead of filing twenty line-level comments about one cause.

skills/cognitive-load/SKILL.md

@@ -347,3 +347,12 @@ type UserWriter interface {
 - Load `refactoring` skill for systematic techniques to reduce identified hotspots
 - Load `solid` skill for structural fixes (coupling, cohesion)
 - Load `clean-code` skill for naming improvements
+
+## Escalation
+
+Read-only measurement. The score is the output.
+
+Stop and hand back when: the measurement disagrees with the reader's lived experience of
+the code. A metric that says "fine" about code everyone finds hard is evidence about the
+metric, not about the code, and continuing to defend the number is how a measure becomes
+a target.

skills/debug/SKILL.md

@@ -12,7 +12,7 @@ description: Systematic hypothesis-first debugging. Generate 3-5 ranked hypothes
 
 Debugging is hypothesis generation, not fix generation. The first instinct — "try this and see if it works" — wastes time and teaches nothing. A disciplined debug session produces a small set of ranked, falsifiable hypotheses, each with a concrete verification command. The fix comes after one hypothesis is confirmed, not before.
 
-**Core principle:** A hypothesis you cannot verify in one command is not a hypothesis — it is a guess.
+**Core principle:** A hypothesis you cannot verify with a single bounded, decisive observation is not a hypothesis — it is a guess. In a repo that observation is usually one command. Above one it may be an instrumented run, or partitioning the last twenty CI runs by trigger type; what makes it a hypothesis is that the observation *discriminates*, not that it fits on one line.
 
 ## When to Use
 
@@ -25,6 +25,27 @@ Debugging is hypothesis generation, not fix generation. The first instinct — "
 - Compile errors with clear messages (just fix the typo)
 - Already-diagnosed bugs where you know the cause (go straight to TDD with a regression test)
 
+### Is it actually diagnosed?
+
+That last exclusion is the one people get wrong, because a confident wrong diagnosis feels
+exactly like a right one. It is diagnosed if you can state the mechanism *and* name the
+observation that would have proved it wrong. If the evidence is "we changed X and it got
+better", that is correlation with a deployment, and this skill applies.
+
+The strongest tell is a run of failed fixes — see below. Three plausible fixes that did
+not eliminate the symptom is not bad luck, it is the diagnosis being wrong.
+
+### Intake: what you need before hypothesising
+
+Before generating anything, confirm you have the failure itself — the error text, the
+stack, the failing run's id, the log. If the report is "it's flaky again" with no
+artifact, **name the specific thing you need and stop**. Iron Law 1 forbids "try X and
+see"; hypothesising into a vacuum is the same failure with better grammar, and it is
+worse because the output looks like analysis.
+
+This is the rule `cad-babysit` already enforces from the other side: read the issue's own
+comments and the job log *first*.
+
 ## Iron Laws
 
 1. **Never suggest "try X and see what happens."** Every hypothesis must have a specific expected outcome if correct.
@@ -76,7 +97,15 @@ For each hypothesis, capture three things:
 - **Verification:** the single command or file inspection that confirms or denies it
 - **Expected outcome if correct:** the specific output you would see
 
-Order by likelihood. The most likely cause is hypothesis 1.
+Order by likelihood, most likely first. **The ordering is the ranking — do not also
+attach `high`/`medium`/`low` labels.** With five slots and three labels the labels stop
+discriminating (two hypotheses are genuinely both "high" and the label cannot say which
+comes first), and a reader then has two orderings that can disagree. Position already
+carries it.
+
+Where you can say *why* one outranks another — a prior brain entry, a matching symptom,
+a recent change in that area — say that instead of a label. That is information; a label
+is a restatement of the order it sits next to.
 
 ### Step 3: Output
 
@@ -140,6 +169,7 @@ The brain holds prior debug sessions across the project. Use it to skip rediscov
 
 **At debug start:**
 - Run `brain_query` with the error message snippet + the package name. Past sessions may have logged identical or similar failures with their resolved hypotheses.
+- **A hit is evidence, so cite it inline in the hypothesis it informs** — `(brain: <entry-name>)` — rather than mentioning it once at the top. If a prior entry is why a hypothesis ranks first, the reader needs that at the hypothesis, not in a preamble. If a prior entry contradicts your ranking, say so and rank it anyway if the evidence here is better; the brain records what was true then.
 
 **After a hypothesis is confirmed:**
 - Run `brain_write` with the failure signature → confirmed mechanism. Future debug sessions on the same area get the answer immediately.
@@ -182,3 +212,13 @@ Techniques kept in `debug/references/`, inherited from the deleted
   including as one of the fixes already tried. A bumped timeout is a symptom.
 - `find-polluter.sh` — run when a test passes alone and fails in the suite, or when
   something in the tree appears that no test admits to creating.
+
+## Escalation
+
+Diagnose only — Iron Law 3 is already an escalation rule: the fix is a separate TDD cycle,
+not this skill's output.
+
+Stop and hand back when: the report contains no failure text and no locator, in which case
+name the specific artifact you need (run id, job log, stack trace) and stop rather than
+hypothesising into a vacuum; or the evidence needed to discriminate between your top two
+hypotheses requires access you do not have.

skills/discovery-framing/SKILL.md

@@ -152,3 +152,12 @@ hand-wavy. Crisp solution + fuzzy problem = reverse-engineered justification. St
 
 > Named instances of both war stories are client-tagged and held out of this public skill
 > pending client-store decision. The transferable lesson lives here; the wrapper stays out.
+
+## Escalation
+
+Advisory. Produces a problem brief; commits to nothing.
+
+Stop and hand back when: the evidence needed to size a problem requires talking to
+customers you cannot reach. Sizing a problem from assumptions and presenting it as
+discovery is worse than saying the number is unknown — it launders a guess into a brief
+that later decisions will cite.

skills/grill-me/SKILL.md

@@ -148,3 +148,12 @@ This skill maps to the **convergence moments** in the Double Diamond workflow:
 - **Mid-Diamond 2 (Develop):** Use Quick Poke when an agent's experiment result is ambiguous and you're deciding whether to continue or pivot.
 
 The skill does NOT replace human judgment at convergence points — it sharpens the plan so that judgment is better informed.
+
+## Escalation
+
+Advisory. Produces sharper questions and a better plan; decides nothing.
+
+Stop and hand back when: the plan's weak point is a decision that is the operator's to
+make rather than a gap in reasoning — surface it as a question with options and a
+recommendation, and do not grill past it. Also stop when a round produces no new
+objection: interrogation past that point manufactures doubt rather than finding it.

skills/solid/SKILL.md

@@ -261,3 +261,12 @@ Domain types know nothing about HTTP, SQL, or external APIs.
 - `references/python-adaptation.md` — the Python rewrite: Protocol over ABC, and what does not carry over from Go
 - Load `clean-code` skill for naming and structure
 - Load `code-review` skill for detecting violations during review
+
+## Escalation
+
+Advisory. Names principle violations and suggests structure; writes no code.
+
+Stop and hand back when: applying a principle would require a change larger than the one
+under discussion. "This wants dependency inversion" on a two-line fix is a design
+conversation, not a review comment, and forcing it through as one is how a small change
+acquires an architecture.

skills/stage-gate-review/SKILL.md

@@ -151,3 +151,12 @@ stays in the client boundary**:
 - Council/forum names, internal stage labels, internal tooling, named contacts, strategy
   specifics, deal terms → client dir/org only, local models only, never the public brain.
 - This skill carries the **pattern**; the client carries the **wrapper**. Never merge them.
+
+## Escalation
+
+Advisory. Prepares or chairs a gate; the council decides, not this skill.
+
+Stop and hand back when: a discipline's evidence is missing rather than weak. A gap on a
+gating discipline means do not bring the ask — bring a feedback-only ask instead. Marking
+it "cleared with a note" is precisely the gate theatre the anti-patterns section is
+about.

skills/tdd/SKILL.md

@@ -365,7 +365,7 @@ Before marking work complete:
 - [ ] Tests use real code (mocks only if crossing a system boundary)
 - [ ] Edge cases and errors covered
 
-Can't check all boxes? You skipped TDD. Start over.
+Can't check **or deliberately strike** all boxes? You skipped TDD. Start over. A box struck with a stated reason is answered; a box left hanging is not.
 
 ## When Stuck
 
@@ -374,7 +374,7 @@ Can't check all boxes? You skipped TDD. Start over.
 | Don't know how to test | Write wished-for API. Write assertion first. Ask Mathias. |
 | Test too complicated | Design too complicated. Simplify interface. |
 | Must mock everything | Code too coupled. Use dependency injection. |
-| Test setup huge | Extract helpers with `t.Helper()`. Still complex? Simplify design. |
+| Test setup huge | Extract helpers (`t.Helper()` in Go, a local `__tracebackhide__ = True` in Python). Still complex? Simplify design. |
 
 ## Debugging Integration
 

skills/telos-load/SKILL.md

@@ -82,3 +82,11 @@ created in a CAD session should trace to a TELOS GOAL. Every GOAL
 traces to a PROBLEM.
 
 Traceability chain: PROBLEM → GOAL → SPEC → TICKET → IMPL → TEST
+
+## Escalation
+
+Read-only. Loads intention context; changes nothing.
+
+Stop and hand back when: the brain is unreachable or returns nothing for the wing. Working
+from a remembered TELOS is the failure this skill exists to prevent — say the load failed
+rather than reconstructing it from memory.

skills/test-design/SKILL.md

@@ -309,3 +309,11 @@ Apply this checklist to every new test:
 - Load `tdd` skill for the full TDD workflow
 - Load `code-review` skill for test quality review during pre-merge review
 - See `clean-code/references/code-smells.md` for testing-specific smells
+
+## Escalation
+
+Read-only scoring of existing tests.
+
+Stop and hand back when: the tests are fine and the *design under test* is what makes them
+awkward. Hard-to-test is a design finding, not a test finding, and rewriting the tests
+around it hides the thing worth knowing.

tests/check_escalation_test.sh

@@ -0,0 +1,85 @@
+#!/bin/sh
+# Tests for bin/check-escalation.
+#
+# #5 asked whether SKILL.md needs first-class failure/escalation fields and
+# decided: not frontmatter (nothing reads it), a body section (the model reads
+# that). #37 then had to define WHICH skills need one, and every obvious answer
+# was bad — a hardcoded list rots, content sniffing is unfalsifiable, a
+# frontmatter flag is the rejected option through the back door.
+#
+# So there is no acting set. EVERY skill answers the question; a read-only one
+# answers it in a line. The classification problem disappears, and "this skill
+# never hands back" becomes a stated claim rather than an absence.
+#
+# bin/escalation-pending.txt is a ratchet for skills whose real rule has not
+# been written yet. It is self-cleaning: a skill that has a section AND is still
+# listed fails, so the list cannot silently outlive its reason.
+
+set -u
+
+ROOT=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+SUT="$ROOT/bin/check-escalation"
+
+pass=0
+fail=0
+WORK=${TMPDIR:-/tmp}/check_escalation_test.$$
+
+if [ ! -f "$SUT" ]; then
+  printf 'FAIL: %s does not exist\n' "$SUT"
+  exit 1
+fi
+
+cleanup() { rm -rf "$WORK"; }
+trap cleanup EXIT INT TERM
+
+# fixture <name> — an empty checkout with a bin/ for the pending list.
+fixture() {
+  _f="$WORK/$1"
+  mkdir -p "$_f/skills" "$_f/bin"
+  : > "$_f/bin/escalation-pending.txt"
+  printf '%s' "$_f"
+}
+
+# skill <root> <name> <has-section>
+skill() {
+  mkdir -p "$1/skills/$2"
+  {
+    printf -- '---\nname: %s\ndescription: d\n---\n\n# %s\n' "$2" "$2"
+    [ "$3" = yes ] && printf '\n## Escalation\n\nStop and hand back when X. Hand back by: saying so.\n'
+  } > "$1/skills/$2/SKILL.md"
+}
+
+# expect <rc> <label> <fixture> [needle]
+expect() {
+  _want=$1; _label=$2; _fx=$3; _needle=${4:-}
+  _out=$(sh "$SUT" "$_fx" 2>&1); _rc=$?
+  if [ "$_rc" -ne "$_want" ]; then
+    fail=$((fail + 1)); printf '  FAIL %s (want rc=%s got %s)\n%s\n' "$_label" "$_want" "$_rc" "$_out"; return
+  fi
+  if [ -n "$_needle" ] && ! printf '%s' "$_out" | grep -q "$_needle"; then
+    fail=$((fail + 1)); printf '  FAIL %s (rc ok, report never says %s)\n%s\n' "$_label" "$_needle" "$_out"; return
+  fi
+  pass=$((pass + 1)); printf '  ok   %s\n' "$_label"
+}
+
+f=$(fixture ok); skill "$f" alpha yes
+expect 0 'a skill with an Escalation section passes' "$f"
+
+f=$(fixture missing); skill "$f" alpha no
+expect 1 'a skill with no section fails, naming it' "$f" 'alpha'
+
+f=$(fixture pending); skill "$f" alpha no; printf 'alpha\n' > "$f/bin/escalation-pending.txt"
+expect 0 'a listed skill is allowed through the ratchet' "$f"
+
+f=$(fixture done); skill "$f" alpha yes; printf 'alpha\n' > "$f/bin/escalation-pending.txt"
+expect 1 'a listed skill that now HAS a section fails — remove it from the list' "$f" 'escalation-pending'
+
+f=$(fixture stale); skill "$f" alpha yes; printf 'ghost\n' > "$f/bin/escalation-pending.txt"
+expect 1 'a listed skill that does not exist fails' "$f" 'ghost'
+
+f=$(fixture comments); skill "$f" alpha no
+printf '# a comment, and a blank line follow\n\nalpha\n' > "$f/bin/escalation-pending.txt"
+expect 0 'comments and blank lines in the list are ignored' "$f"
+
+printf '\ncheck_escalation: %d passed, %d failed\n' "$pass" "$fail"
+[ "$fail" -eq 0 ]