fix(setup): keep Claude memory subagents as leaf writers

internal/setup/assets/claude/SKILL.md

@@ -50,7 +50,8 @@ Check the output `errors` field because imports can partially succeed.
 
 ## Guardrails
 
-- Never run `remember` or `link` in the main conversation — always delegate to a sub-agent.
+- Main conversation: never run `remember` or `link` directly; delegate to a Task sub-agent.
+- Memory sub-agent: you are the leaf writer. Run `mnemon remember` and any justified `mnemon link` commands directly; do not spawn another sub-agent.
 - Do not store secrets, passwords, or tokens.
 - Categories: `preference` · `decision` · `insight` · `fact` · `context`
 - Edge types: `temporal` · `semantic` · `causal` · `entity`

internal/setup/assets/claude/guide.md

@@ -53,9 +53,10 @@ Aim for a rough distribution: ~20% at 4-5, ~50% at 2-3, ~30% at 1.
 Avoid defaulting everything to 4-5 — that defeats the scoring system.
 
 **What to store**: both conclusions AND context. Prefer storing a little too much over missing something useful.
-**How to store**: delegate to a Task sub-agent (`subagent_type="general-purpose"`, `model="sonnet"`).
+**How to store from the main conversation**: delegate to a Task sub-agent (`subagent_type="general-purpose"`, `model="sonnet"`).
 Only provide what to store — content, category, importance, entities, and create/update intent.
-The sub-agent will read the mnemon skill and execute the correct commands itself.
+The sub-agent is the leaf memory writer: it will read the mnemon skill and execute `mnemon remember` / `mnemon link` itself.
 
 Do NOT: write CLI commands or workflow steps in the sub-agent prompt (the sub-agent has access to the skill docs and will use the correct flags).
-Do NOT run memory writes in the main conversation, or remember operational/public/git-tracked/transient info.
+Do NOT run memory writes in the main conversation, or remember operational/public/git-tracked/transient info.
+Do NOT ask the memory sub-agent to delegate again; nested memory sub-agents waste tokens and can fail in Claude Code.

internal/setup/assets/claude/stop.sh

@@ -12,4 +12,9 @@ if echo "$MSG" | grep -qiE "mnemon remember|sub-agent.*remember|Stored.*imp="; t
   exit 0
 fi
 
+if echo "$INPUT" | grep -qE '"hook_event_name"[[:space:]]*:[[:space:]]*"SubagentStop"|"agent_id"[[:space:]]*:'; then
+  echo "[mnemon] If this sub-agent was delegated memory work, complete it directly with mnemon remember/link; do not spawn another sub-agent. If no durable memory is needed, say so and finish."
+  exit 0
+fi
+
 echo "[mnemon] Consider: does this exchange warrant a remember sub-agent?"

internal/setup/claude_test.go

@@ -3,7 +3,10 @@ package setup
 import (
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
+
+	"github.com/mnemon-dev/mnemon/internal/setup/assets"
 )
 
 func TestPromptDirHonorsMnemonDataDir(t *testing.T) {
@@ -61,6 +64,51 @@ func TestWritePromptFilesWritesUnderMnemonDataDir(t *testing.T) {
 	}
 }
 
+func TestClaudeMemoryInstructionsKeepSubagentsLeafWriters(t *testing.T) {
+	tests := []struct {
+		name string
+		body string
+		want []string
+	}{
+		{
+			name: "guide",
+			body: string(assets.ClaudeGuide),
+			want: []string{
+				"The sub-agent is the leaf memory writer",
+				"Do NOT ask the memory sub-agent to delegate again",
+			},
+		},
+		{
+			name: "skill",
+			body: string(assets.ClaudeSkill),
+			want: []string{
+				"Main conversation: never run `remember` or `link` directly",
+				"Memory sub-agent: you are the leaf writer",
+				"do not spawn another sub-agent",
+			},
+		},
+		{
+			name: "stop hook",
+			body: string(assets.ClaudeStopHook),
+			want: []string{
+				`"hook_event_name"[[:space:]]*:[[:space:]]*"SubagentStop"`,
+				"complete it directly with mnemon remember/link",
+				"do not spawn another sub-agent",
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			for _, want := range tt.want {
+				if !strings.Contains(tt.body, want) {
+					t.Fatalf("%s is missing %q", tt.name, want)
+				}
+			}
+		})
+	}
+}
+
 func TestCollidesWithUserConfigHomeInstall(t *testing.T) {
 	home := t.TempDir()
 	t.Setenv("HOME", home)