diff --git a/.claude/skills/grill/SKILL.md b/.claude/skills/grill/SKILL.md
index 7fb290f..7431d71 100644
--- a/.claude/skills/grill/SKILL.md
+++ b/.claude/skills/grill/SKILL.md
@@ -9,6 +9,12 @@ Ask the questions one at a time, waiting for feedback on each before continuing.
 
 If a question can be answered by exploring the codebase, explore the codebase instead of asking it.
 
+**Never start implementation during or after the interview without an explicit instruction from the user.** This applies at every point — mid-interview and after the final question alike.
+
+## Closing the interview
+
+When every branch carries an explicit decision and no dependency is left open, produce a concise summary of all decisions reached, then stop and wait for the user's next instruction.
+
 ## Tracking the domain model as you go
 
 If a `.claude/CONTEXT.md` file exists in the project, also run [`domain-modeling`](../domain-modeling/SKILL.md) alongside this interview: resolve each term into `.claude/CONTEXT.md` the moment it crystallizes, and offer an ADR using that skill's own criteria — hard to reverse, surprising without context, and the result of a real trade-off. If no `.claude/CONTEXT.md` exists, run the interview alone with no doc side effects.