Remove "It assumes one writer" section from grill-with-docs docs

The section's single-writer framing doesn't fit how the skill is actually used across a team; drop it rather than carry a stale caveat.

.agents/invocation.md

@@ -19,6 +19,8 @@ This is about **operative** instructions — a skill's own steps telling the age
 
 The Skill tool takes one skill per call. A step that needs two skills is two calls, not one call with two names — say so (`Call the Skill tool twice, for "grilling" and "domain-modeling"`), not "call it with X and Y," which reads as a single call taking both.
 
+This whole convention only holds when the named skill is **model-invoked**. A user-invoked skill can never be reached this way, full stop — per the invariant above, no other skill can call it, including by naming it to the Skill tool. When a step's precondition is a user-invoked skill (e.g. `setup-matt-pocock-skills`), phrase it as an instruction for the human to act on — "tell the user to run `/setup-matt-pocock-skills`" — never as a Skill tool call.
+
 ## Passive vs active domain work
 
 Merely _reading_ `CONTEXT.md` for vocabulary is a one-line prose pointer, not the `domain-modeling` skill. Only the active build/sharpen discipline (challenge terms, edge-case scenarios, write ADRs, update `CONTEXT.md` inline) is `domain-modeling`.

.changeset/grilling-remove-em-dashes.md

@@ -0,0 +1,5 @@
+---
+"mattpocock-skills": patch
+---
+
+grilling: remove em-dashes from `SKILL.md`, replacing them with colons and semicolons so the instructions read as plain text.

.changeset/user-invoked-skill-invocation.md

@@ -0,0 +1,11 @@
+---
+"mattpocock-skills": patch
+---
+
+Stop skills from trying to reach user-invoked skills through the Skill tool — fix cross-skill references that violated the "no other skill can call it" invariant in `.agents/invocation.md`, in `to-spec`, `wayfinder`, `to-tickets`, `triage`, `code-review`, and `diagnosing-bugs`.
+
+- `to-spec`, `wayfinder`, `to-tickets`, `triage`, and `code-review` each carried a precondition ("...run `/setup-matt-pocock-skills` if not") that PR #878 rewrote into a literal `Call the Skill tool with "setup-matt-pocock-skills"` instruction. `setup-matt-pocock-skills` is user-invoked, so none of these skills — user-invoked or model-invoked — can call it. Reworded all five as instructions for the agent to tell the human to run it instead.
+- `diagnosing-bugs`'s Phase 6 post-mortem hand off to `improve-codebase-architecture` (also user-invoked) the same way, from an autonomous, often-unattended bug-fixing flow with no human in the loop to catch the failed call. Removed the hand-off outright rather than softening it — it rarely fired in practice. Phase 6 is now "Cleanup" only; the mechanical checklist is untouched.
+- Added a carve-out paragraph to `.agents/invocation.md`'s "Dependencies between them" section: the `Call the Skill tool with "name"` convention only applies when the named skill is model-invoked. This is the section PR #878 introduced without reconciling it against the user-invoked/model-invoked invariant stated eight lines above it — the gap is most of why this bug reached six call sites instead of one.
+
+Fixes #453.

docs/engineering/grill-with-docs.md

@@ -40,12 +40,6 @@ That third row is the one that catches people out. `CONTEXT.md` is a glossary an
 
 The glossary is the point. Domain language is the thing this skill is actually building — the project's own words, agreed once, so you, the agent and your colleagues stop paying to re-derive them. It is worth saying that not everyone agrees this buys you agent performance: the sharpest public pushback is that a term and its plain-English expansion get the same result from the [model](https://www.aihero.dev/ai-coding-dictionary/model), and that the vocabulary really compresses communication between the humans who share it. That reading still leaves the glossary valuable; it just moves the value.
 
-## It assumes one writer
-
-The stateful outputs assume a single person curating them. A two-developer team running four months in one repo reported state drift on roughly 20% of sampled merged PRs, with ADR citations and README claims the highest-drift surfaces — deliberate, human-curated docs drifted worse than agent memory did. Pruning the stale docs did not hold; the same sweep was stale again within days. What worked was deleting shadow state outright and adding a deterministic citation and link linter to CI.
-
-Related: running the skill repeatedly across unrelated changes in one repo tends to accumulate mixed-topic docs, because nothing separates one session's output from another's. Neither of these is fixed in the skill today.
-
 ## Common questions
 
 **Should I use this or `/wayfinder`?**

skills/engineering/code-review/SKILL.md

@@ -10,7 +10,7 @@ Two-axis review of the diff between `HEAD` and a fixed point the user supplies:
 
 Both axes run as **parallel sub-agents** so they don't pollute each other's context, then this skill aggregates their findings.
 
-The issue tracker should have been provided to you — call the Skill tool with "setup-matt-pocock-skills" if `docs/agents/issue-tracker.md` is missing.
+The issue tracker should have been provided to you. If `docs/agents/issue-tracker.md` is missing, tell the user to run `/setup-matt-pocock-skills`.
 
 ## Process
 

skills/engineering/diagnosing-bugs/SKILL.md

@@ -127,7 +127,7 @@ If a correct seam exists:
 4. Watch it pass.
 5. Re-run the Phase 1 feedback loop against the original (un-minimised) scenario.
 
-## Phase 6 — Cleanup + post-mortem
+## Phase 6 — Cleanup
 
 Required before declaring done:
 
@@ -136,5 +136,3 @@ Required before declaring done:
 - [ ] All `[DEBUG-...]` instrumentation removed (`grep` the prefix)
 - [ ] Throwaway prototypes deleted (or moved to a clearly-marked debug location)
 - [ ] The hypothesis that turned out correct is stated in the commit / PR message — so the next debugger learns
-
-**Then ask: what would have prevented this bug?** If the answer involves architectural change (no good test seam, tangled callers, hidden coupling) hand off by calling the Skill tool with "improve-codebase-architecture" and the specifics. Make the recommendation **after** the fix is in, not before — you have more information now than when you started.

skills/engineering/to-spec/SKILL.md

@@ -6,7 +6,7 @@ disable-model-invocation: true
 
 This skill takes the current conversation context and codebase understanding and produces a spec. Do NOT interview the user — just synthesize what you already know.
 
-The issue tracker and triage label vocabulary should have been provided to you — call the Skill tool with "setup-matt-pocock-skills" if not.
+The issue tracker and triage label vocabulary should have been provided to you. If not, tell the user to run `/setup-matt-pocock-skills`.
 
 ## Process
 

skills/engineering/to-tickets/SKILL.md

@@ -8,7 +8,7 @@ disable-model-invocation: true
 
 Break a plan, spec, or conversation into a set of **tickets** — tracer-bullet vertical slices, each declaring the tickets that **block** it.
 
-The issue tracker and triage label vocabulary should have been provided to you — call the Skill tool with "setup-matt-pocock-skills" if not.
+The issue tracker and triage label vocabulary should have been provided to you. If not, tell the user to run `/setup-matt-pocock-skills`.
 
 ## Process
 

skills/engineering/triage/SKILL.md

@@ -40,7 +40,7 @@ For a PR, the same states read against the attached code: `ready-for-agent` mean
 
 Every triaged issue should carry exactly one category role and one state role. If state roles conflict, flag it and ask the maintainer before doing anything else.
 
-These are canonical role names — the actual label strings used in the issue tracker may differ. The mapping should have been provided to you - call the Skill tool with "setup-matt-pocock-skills" if not.
+These are canonical role names — the actual label strings used in the issue tracker may differ. The mapping should have been provided to you. If not, tell the user to run `/setup-matt-pocock-skills`.
 
 State transitions: an unlabeled issue normally goes to `needs-triage` first; from there it moves to `needs-info`, `ready-for-agent`, `ready-for-human`, or `wontfix`. `needs-info` returns to `needs-triage` once the reporter replies. The maintainer can override at any time — flag transitions that look unusual and ask before proceeding.
 

skills/engineering/wayfinder/SKILL.md

@@ -22,7 +22,7 @@ The map is a single issue on this repo's issue tracker, labelled `wayfinder:map`
 
 The map is an **index**, not a store. It lists the decisions made and points at the tickets that hold their detail; a decision lives in exactly one place — its ticket — so the map never restates it, only gists it and links.
 
-**Where the map, its child tickets, blocking, and frontier queries physically live is tracker-specific.** The issue tracker should have been provided to you — call the Skill tool with "setup-matt-pocock-skills" if not. Consult the tracker doc's "Wayfinding operations" section for how _this_ repo expresses them. If no tracker has been provided, default to the local-markdown tracker.
+**Where the map, its child tickets, blocking, and frontier queries physically live is tracker-specific.** The issue tracker should have been provided to you. If not, tell the user to run `/setup-matt-pocock-skills`. Consult the tracker doc's "Wayfinding operations" section for how _this_ repo expresses them. If no tracker has been provided, default to the local-markdown tracker.
 
 ### The map body
 

skills/productivity/grilling/SKILL.md

@@ -5,7 +5,7 @@ description: Grill the user relentlessly about a plan, decision, or idea. Use wh
 
 Interview the user relentlessly until you reach a shared understanding. Map this as a **design tree**: every decision branches into the decisions that hang off it.
 
-Work the tree in **rounds**. The **frontier** is every decision whose prerequisites are already settled — the questions you can ask _now_ without guessing at answers you haven't heard yet. Ask the whole frontier in one round: number each question and give your recommended answer. Then wait for the user's answers before the next round.
+Work the tree in **rounds**. The **frontier** is every decision whose prerequisites are already settled: the questions you can ask _now_ without guessing at answers you haven't heard yet. Ask the whole frontier in one round: number each question and give your recommended answer. Then wait for the user's answers before the next round.
 
 Each question should be formatted like so:
 
@@ -15,8 +15,8 @@ Each question should be formatted like so:
 ➡️ <your recommended answer>
 ```
 
-Each round the user answers reshapes the tree — settled decisions push the frontier outward and unblock questions that depended on them. Recompute the frontier and ask the next round. A question whose answer depends on another question still open in this round belongs to a _later_ round, not this one.
+Each round the user answers reshapes the tree: settled decisions push the frontier outward and unblock questions that depended on them. Recompute the frontier and ask the next round. A question whose answer depends on another question still open in this round belongs to a _later_ round, not this one.
 
-Finding _facts_ is your job, never the user's. When a frontier question needs a fact from the environment (filesystem, tools, etc.), dispatch a sub-agent to find it — don't ask the user for anything you could look up yourself. Don't block on it: a running exploration is an unsettled prerequisite, so only the questions downstream of it wait for the sub-agent to report — ask the rest of the frontier now. The _decisions_ are the user's — put each to them and wait.
+Finding _facts_ is your job, never the user's. When a frontier question needs a fact from the environment (filesystem, tools, etc.), dispatch a sub-agent to find it; don't ask the user for anything you could look up yourself. Don't block on it: a running exploration is an unsettled prerequisite, so only the questions downstream of it wait for the sub-agent to report; ask the rest of the frontier now. The _decisions_ are the user's: put each to them and wait.
 
 The session is done when the frontier is empty: every branch of the design tree visited, nothing left silently assumed. Do not act on it until the user confirms you have reached a shared understanding.