fix(skills): brainstorming gate exempts nothing-to-design requests; description exceptions are authoritative (SUP-333 C)

Consolidates the brainstorming exception with its routing-layer
semantics, so this PR is independently mergeable (previously split
across two stacked PRs whose intermediate state left the always-
injected routing text contradicting the shipped description).

brainstorming: the nothing-to-design exception, earned by a tripwire
scan stated in one line before acting. Tripwires precede the
permission (skimmers stop at "implement directly"); security-posture
touches re-gate even with the exact value stated; requested deletions
re-gate; rationalization table per writing-skills bulletproofing.
Description 971/1024 chars, YAML-validated.

using-superpowers: description-level exceptions are authoritative
(compliance, not rationalization); doubt means invoke; only the
description can define one; the skip must state its scan; flowchart
routes the exempt path through the scan statement;
<EXTREMELY-IMPORTANT> defers in one parenthetical.

writing-skills: negative triggering conditions are scope (allowed,
required at the description) vs workflow summaries (still forbidden) —
prevents a future checklist pass from stripping the exception.

Eval evidence (quorum): RED cost-checkbox-over-trigger failed 5/6
agents (pi ⊘); GREEN claude 3/3, codex ✓, antigravity ✓ (kimi
unchanged from baseline — does not read description exceptions);
gate-still-fires: brainstorming-resists 2/2 + codex, spec-plan
brainstorm leg 3/3. Boundary scenarios (security one-liner, requested
deletion): pre-stack dev baseline 0/3 + 0/3 (silent edit every time —
the blanket gate never fired on one-liners); this text 2/3 + 2/3, the
first text in the corpus to catch these at any rate; scenarios ship as
regression instruments (proposed in prime-radiant-inc/superpowers-evals#11, open).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Canary-caught addition: on the assembled text, triggering-writing-plans
went 0/3 with claude citing "your explicit instruction wins per the
priority rules" to skip writing-plans under the scenario's "don't ask
me any questions" pressure — the Instruction Priority section read as
licensing ad-hoc pressure to skip workflow steps. User Instructions now
distinguishes pressure phrasing (changes interaction style) from
instructions that name what to skip (honored), and tags the quoted
rationalization.

skills/brainstorming/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: brainstorming
-description: "You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation."
+description: "You MUST use this before any creative work - creating features, building components, adding functionality, or modifying behavior. Explores user intent, requirements and design before implementation. The one exception (nothing-to-design) must be EARNED by a tripwire scan first - invoke this skill if the change: adds a file or dependency; touches a schema, API contract, or persisted data (even when the user stated the outcome); deletes or disables working functionality (even when asked); touches security posture at all (auth, sessions, timeouts, permissions, CORS, crypto - even with the exact value stated); alters user-visible behavior beyond the stated change; has more than one plausible reading; or is framed as a feature or project. Only when NO tripwire hits and the outcome is fully specified (e.g. 'add a basic checkbox, nothing fancy' where context leaves nothing to choose): state your scan in one line, then implement directly without invoking this skill."
 ---
 
 # Brainstorming Ideas Into Designs
@@ -10,12 +10,22 @@ Help turn ideas into fully formed designs and specs through natural collaborativ
 Start by understanding the current project context, then ask questions one at a time to refine the idea. Once you understand what you're building, present the design and get user approval.
 
 <HARD-GATE>
-Do NOT invoke any implementation skill, write any code, scaffold any project, or take any implementation action until you have presented a design and the user has approved it. This applies to EVERY project regardless of perceived simplicity.
+Do NOT invoke any implementation skill, write any code, scaffold any project, or take any implementation action until you have presented a design and the user has approved it. This applies to EVERY project regardless of perceived simplicity, with exactly one exception.
+
+Exception — nothing to design: when the exception in this skill's description applies (zero open design decisions; its tripwire list puts the gate back on), implement directly. TDD and verification-before-completion still apply. Brainstorming exists to surface decisions; when there are none, the user's request IS the design. Any doubt: the gate holds.
 </HARD-GATE>
 
 ## Anti-Pattern: "This Is Too Simple To Need A Design"
 
-Every project goes through this process. A todo list, a single-function utility, a config change — all of them. "Simple" projects are where unexamined assumptions cause the most wasted work. The design can be short (a few sentences for truly simple projects), but you MUST present it and get approval.
+Anything with open decisions goes through this process. A todo list, a single-function utility, a data migration — "simple" projects are where unexamined assumptions cause the most wasted work. The design can be short (a few sentences for truly simple projects), but if anything remains to decide, you MUST present it and get approval. Do not confuse this with the nothing-to-design exception above: "this seems simple, I'll skip the design" is a rationalization whenever decisions exist.
+
+| Excuse | Reality |
+|--------|---------|
+| "The codebase has an established pattern, so nothing is open" | A pattern answers HOW, not WHETHER or WHAT. Those decisions are still open unless the user made them. |
+| "I can infer the obvious choice" | If there is a choice to infer, a decision is open. Invoke. |
+| "The user said keep it simple / nothing fancy" | A hedge describes the solution's size, not the request's completeness. Check what remains undecided, not the tone. |
+| "Asking would waste the user's time" | One design question costs seconds; an unexamined assumption costs a rewrite. |
+| "The user already made that decision — they told me to delete it" | A requested deletion still has consequences the user may not have weighed (working feature, no usage data, alternatives). Surface them first; the tripwire applies to requested deletions. |
 
 ## Checklist
 

skills/using-superpowers/SKILL.md

@@ -12,7 +12,7 @@ If you think there is even a 1% chance a skill might apply to what you are doing
 
 IF A SKILL APPLIES TO YOUR TASK, YOU DO NOT HAVE A CHOICE. YOU MUST USE IT.
 
-This is not negotiable. This is not optional. You cannot rationalize your way out of this.
+This is not negotiable. This is not optional. You cannot rationalize your way out of this. (The single carve-out: a skill whose own description says it does not apply — see The Rule.)
 </EXTREMELY-IMPORTANT>
 
 ## Instruction Priority
@@ -49,6 +49,10 @@ Skills speak in actions ("dispatch a subagent", "create a todo", "read a file")
 
 **Invoke relevant or requested skills BEFORE any response or action.** Even a 1% chance a skill might apply means that you should invoke the skill to check. If an invoked skill turns out to be wrong for the situation, you don't need to use it.
 
+**Documented exceptions in a skill's own description are authoritative.** When a description itself says the skill does not apply to a request (e.g. brainstorming's nothing-to-design exception), not invoking it is compliance, not rationalization. Any doubt about whether the exception's conditions hold means invoke. Only the skill's description can define such an exception; you cannot infer one.
+
+**An exception skip must be stated, never silent.** Before your first action, write one line naming the exception and the tripwire scan that came up empty — e.g. "Skipping brainstorming per its exception: no security/deletion/schema/new-file tripwires; outcome fully specified." If you did not write the scan line, you did not scan — invoke the skill instead.
+
 ```dot
 digraph skill_flow {
     "User message received" [shape=doublecircle];
@@ -69,7 +73,12 @@ digraph skill_flow {
     "Invoke brainstorming skill" -> "Might any skill apply?";
 
     "User message received" -> "Might any skill apply?";
-    "Might any skill apply?" -> "Invoke the skill" [label="yes, even 1%"];
+    "Might any skill apply?" -> "Skill's own description exempts this request?" [label="yes, even 1%"];
+    "Skill's own description exempts this request?" [shape=diamond];
+    "Skill's own description exempts this request?" -> "Invoke the skill" [label="no / any doubt"];
+    "Skill's own description exempts this request?" -> "State the one-line tripwire scan, then proceed" [label="yes, clearly"];
+    "State the one-line tripwire scan, then proceed" [shape=box];
+    "State the one-line tripwire scan, then proceed" -> "Respond (including clarifications)";
     "Might any skill apply?" -> "Respond (including clarifications)" [label="definitely not"];
     "Invoke the skill" -> "Announce: 'Using [skill] to [purpose]'";
     "Announce: 'Using [skill] to [purpose]'" -> "Has checklist?";
@@ -94,6 +103,7 @@ These thoughts mean STOP—you're rationalizing:
 | "I remember this skill" | Skills evolve. Read current version. |
 | "This doesn't count as a task" | Action = task. Check for skills. |
 | "The skill is overkill" | Simple things become complex. Use it. |
+| "Too trivial to scan the tripwire list" | The scan is one sentence. Write it or invoke the skill. |
 | "I'll just do this one thing first" | Check BEFORE doing anything. |
 | "This feels productive" | Undisciplined action wastes time. Skills prevent this. |
 | "I know what that means" | Knowing the concept ≠ using the skill. Invoke it. |
@@ -118,4 +128,6 @@ The skill itself tells you which.
 
 ## User Instructions
 
-Instructions say WHAT, not HOW. "Add X" or "Fix Y" doesn't mean skip workflows.
+Instructions say WHAT, not HOW. "Add X" or "Fix Y" doesn't mean skip workflows — unless a skill's own description exempts the request (see The Rule above).
+
+Pressure phrasing — "don't ask questions", "make assumptions", "just build it" — changes how you interact (state assumptions instead of asking), not which skills you invoke. Only an instruction that names what to skip ("don't write a plan", "skip TDD") or a description exception skips a workflow step. "Your instruction wins per the priority rules" applied to an unnamed workflow step is a rationalization.

skills/writing-skills/SKILL.md

@@ -151,6 +151,8 @@ Concrete results
 
 The description should ONLY describe triggering conditions. Do NOT summarize the skill's process or workflow in the description.
 
+(Negative triggering conditions are still triggering conditions: a description MAY state when the skill does NOT apply — including its tripwires — and per using-superpowers' Rule such description-level exceptions are authoritative, so they must live here, not only in the body. That is scope, not workflow.)
+
 **Why this matters:** Testing revealed that when a description summarizes the skill's workflow, an agent may follow the description instead of reading the full skill content. A description saying "code review between tasks" caused an agent to do ONE review, even though the skill's flowchart clearly showed TWO reviews (spec compliance then code quality).
 
 When the description was changed to just "Use when executing implementation plans with independent tasks" (no workflow summary), the agent correctly read the flowchart and followed the two-stage review process.