diff --git a/cmd/hook.go b/cmd/hook.go
index 1f54c519..94e65420 100644
--- a/cmd/hook.go
+++ b/cmd/hook.go
@@ -48,6 +48,8 @@ func init() {
 	hookCmd.AddCommand(hookPreToolUseCmd)
 
 	hookSessionStartCmd.Flags().StringVar(&hookSessionStartHost, "host", hookHostClaude, "Hook host output format")
+	hookSessionStartCmd.Flags().StringVar(&hookSessionStartPluginName, "plugin-name", "", "Claude Code plugin name")
+	hookPreToolUseCmd.Flags().StringVar(&hookPreToolUsePluginName, "plugin-name", "", "Claude Code plugin name")
 }
 
 var hookCmd = &cobra.Command{
@@ -55,7 +57,11 @@ var hookCmd = &cobra.Command{
 	Short: "Hook handlers for AI coding agent integration",
 }
 
-var hookSessionStartHost string
+var (
+	hookSessionStartHost       string
+	hookSessionStartPluginName string
+	hookPreToolUsePluginName   string
+)
 
 var hookSessionStartCmd = &cobra.Command{
 	Use:   "session-start [mcp-name]",
@@ -104,7 +110,7 @@ func runHookSessionStart(_ *cobra.Command, args []string) error {
 		cwd, _ = os.Getwd()
 	}
 
-	content := generateSessionContextForHost(host, mcpName, cwd)
+	content := generateSessionContextForHost(host, mcpName, hookSessionStartPluginName, cwd)
 	out := sessionStartOutput(host, content)
 
 	enc := json.NewEncoder(os.Stdout)
@@ -112,16 +118,23 @@ func runHookSessionStart(_ *cobra.Command, args []string) error {
 	return enc.Encode(out)
 }
 
-func generateSessionContextForHost(host, mcpName, cwd string) string {
-	return generateSessionContextInternalWithDirective(sessionStartDirective(host, mcpName), cwd, config.FindDonorIndex, spawnBackgroundIndexer)
+func generateSessionContextForHost(host, mcpName, pluginName, cwd string) string {
+	return generateSessionContextInternalWithDirective(sessionStartDirective(host, mcpName, pluginName), cwd, config.FindDonorIndex, spawnBackgroundIndexer)
 }
 
-func sessionStartDirective(host, mcpName string) string {
+func sessionStartDirective(host, mcpName, pluginName string) string {
 	if host == hookHostCursor {
 		return "Use the Lumen semantic_search tool first for any code discovery task — before Grep, Bash, or Read."
 	}
-	toolRef := "mcp__" + mcpName + "__semantic_search"
-	return "Call " + toolRef + " first for any code discovery task — before Grep, Bash, or Read."
+	toolRef := mcpToolReference(pluginName, mcpName, "semantic_search")
+	return "Load and call " + toolRef + " first for any code discovery task — before Grep, Bash, or Read."
+}
+
+func mcpToolReference(pluginName, mcpName, toolName string) string {
+	if pluginName != "" {
+		mcpName = "plugin_" + pluginName + "_" + mcpName
+	}
+	return "mcp__" + mcpName + "__" + toolName
 }
 
 func generateSessionContextInternalWithDirective(directive, cwd string, findDonor func(string, string) string, bgIndexer func(string)) string {
@@ -190,7 +203,7 @@ func generateSessionContextInternalWithDirective(directive, cwd string, findDono
 // findDonor and bgIndexer are injected so tests can verify behaviour without
 // spawning real processes or requiring a live git repository.
 func generateSessionContextInternal(cwd string, findDonor func(string, string) string, bgIndexer func(string)) string {
-	return generateSessionContextInternalWithDirective(sessionStartDirective(hookHostClaude, "lumen"), cwd, findDonor, bgIndexer)
+	return generateSessionContextInternalWithDirective(sessionStartDirective(hookHostClaude, "lumen", ""), cwd, findDonor, bgIndexer)
 }
 
 func normalizeHookHost(host string) (string, error) {
@@ -243,7 +256,7 @@ func runHookPreToolUse(_ *cobra.Command, args []string) error {
 		return nil
 	}
 
-	result := evaluateToolCall(input, mcpName)
+	result := evaluateToolCall(input, mcpName, hookPreToolUsePluginName)
 	if result == nil {
 		// Silent allow — exit 0 with no stdout.
 		return nil
@@ -257,7 +270,7 @@ func runHookPreToolUse(_ *cobra.Command, args []string) error {
 // evaluateToolCall determines whether a tool call should be intercepted
 // with a suggestion to use semantic search instead.
 // Returns nil for silent allow (no output), or a hookOutput with a suggestion.
-func evaluateToolCall(input preToolUseInput, mcpName string) *hookOutput {
+func evaluateToolCall(input preToolUseInput, mcpName, pluginName string) *hookOutput {
 	switch input.ToolName {
 	case "Grep", "Glob":
 		// Always suggest semantic search for any file/code search.
@@ -270,12 +283,12 @@ func evaluateToolCall(input preToolUseInput, mcpName string) *hookOutput {
 		return nil
 	}
 
-	toolRef := "mcp__" + mcpName + "__semantic_search"
+	toolRef := mcpToolReference(pluginName, mcpName, "semantic_search")
 	return &hookOutput{
 		HookSpecificOutput: hookSpecificOutput{
 			HookEventName: "PreToolUse",
 			AdditionalContext: fmt.Sprintf(
-				"Use %s instead of Grep/Glob/find/rg for significantly faster and better search results to reduce context window use and give better quality results.",
+				"Load and call %s instead of Grep/Glob/find/rg for significantly faster and better search results to reduce context window use and give better quality results.",
 				toolRef,
 			),
 		},
diff --git a/cmd/hook_test.go b/cmd/hook_test.go
index d0a6be0b..880b273a 100644
--- a/cmd/hook_test.go
+++ b/cmd/hook_test.go
@@ -62,7 +62,7 @@ func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
 
-func TestGenerateSessionContext_NoIndex(t *testing.T) {
+func TestGenerateSessionContext_NoIndexLegacyToolName(t *testing.T) {
 	// Use the internal version with a no-op bgIndexer to avoid spawning the
 	// test binary as a background process (which would trigger a fork bomb:
 	// the spawned binary runs all tests, which spawn more binaries, etc.)
@@ -71,16 +71,50 @@ func TestGenerateSessionContext_NoIndex(t *testing.T) {
 		func(_ string) {},
 	)
 	if !strings.Contains(content, "mcp__lumen__semantic_search") {
-		t.Error("content should reference the semantic_search tool")
+		t.Error("legacy content should reference the standalone semantic_search tool")
 	}
 	if strings.Contains(content, "EXTREMELY_IMPORTANT") {
 		t.Error("content should not contain EXTREMELY_IMPORTANT directives")
 	}
 }
 
+func TestMCPToolReference(t *testing.T) {
+	tests := []struct {
+		name       string
+		pluginName string
+		want       string
+	}{
+		{
+			name:       "plugin qualified",
+			pluginName: "lumen",
+			want:       "mcp__plugin_lumen_lumen__semantic_search",
+		},
+		{
+			name: "standalone",
+			want: "mcp__lumen__semantic_search",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := mcpToolReference(tt.pluginName, "lumen", "semantic_search")
+			if got != tt.want {
+				t.Fatalf("mcpToolReference() = %q, want %q", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestSessionStartDirectiveClaudePlugin(t *testing.T) {
+	const want = "Load and call mcp__plugin_lumen_lumen__semantic_search first for any code discovery task — before Grep, Bash, or Read."
+	if got := sessionStartDirective(hookHostClaude, "lumen", "lumen"); got != want {
+		t.Fatalf("sessionStartDirective() = %q, want %q", got, want)
+	}
+}
+
 func TestGenerateSessionContextForCursor_NoIndex(t *testing.T) {
 	content := generateSessionContextInternalWithDirective(
-		sessionStartDirective(hookHostCursor, "lumen"),
+		sessionStartDirective(hookHostCursor, "lumen", "lumen"),
 		"/nonexistent/path",
 		func(_, _ string) string { return "" },
 		func(_ string) {},
@@ -107,7 +141,7 @@ func TestEvaluateToolCall_GrepAlwaysSuggests(t *testing.T) {
 				ToolName: "Grep",
 				Input:    map[string]any{"pattern": pattern},
 			}
-			result := evaluateToolCall(input, "lumen")
+			result := evaluateToolCall(input, "lumen", "lumen")
 			if result == nil {
 				t.Fatal("expected suggestion for Grep, got nil")
 				return
@@ -115,8 +149,8 @@ func TestEvaluateToolCall_GrepAlwaysSuggests(t *testing.T) {
 			if result.HookSpecificOutput.PermissionDecision != "" {
 				t.Errorf("expected no permissionDecision, got %q", result.HookSpecificOutput.PermissionDecision)
 			}
-			if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__lumen__semantic_search") {
-				t.Error("additionalContext should reference semantic_search tool")
+			if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
+				t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
 			}
 		})
 	}
@@ -127,7 +161,7 @@ func TestEvaluateToolCall_GlobAlwaysSuggests(t *testing.T) {
 		ToolName: "Glob",
 		Input:    map[string]any{"pattern": "**/*.go"},
 	}
-	result := evaluateToolCall(input, "lumen")
+	result := evaluateToolCall(input, "lumen", "lumen")
 	if result == nil {
 		t.Fatal("expected suggestion for Glob, got nil")
 		return
@@ -135,6 +169,9 @@ func TestEvaluateToolCall_GlobAlwaysSuggests(t *testing.T) {
 	if result.HookSpecificOutput.PermissionDecision != "" {
 		t.Errorf("expected no permissionDecision, got %q", result.HookSpecificOutput.PermissionDecision)
 	}
+	if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
+		t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
+	}
 }
 
 func TestEvaluateToolCall_OtherToolSilentAllow(t *testing.T) {
@@ -142,7 +179,7 @@ func TestEvaluateToolCall_OtherToolSilentAllow(t *testing.T) {
 		ToolName: "Read",
 		Input:    map[string]any{"path": "/some/file.go"},
 	}
-	result := evaluateToolCall(input, "lumen")
+	result := evaluateToolCall(input, "lumen", "lumen")
 	if result != nil {
 		t.Errorf("expected nil (silent allow) for Read, got suggestion")
 	}
@@ -160,13 +197,13 @@ func TestEvaluateToolCall_BashGrepSuggests(t *testing.T) {
 				ToolName: "Bash",
 				Input:    map[string]any{"command": cmd},
 			}
-			result := evaluateToolCall(input, "lumen")
+			result := evaluateToolCall(input, "lumen", "lumen")
 			if result == nil {
 				t.Fatal("expected suggestion for bash grep, got nil")
 				return
 			}
-			if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__lumen__semantic_search") {
-				t.Error("additionalContext should reference semantic_search tool")
+			if !strings.Contains(result.HookSpecificOutput.AdditionalContext, "mcp__plugin_lumen_lumen__semantic_search") {
+				t.Error("additionalContext should reference the plugin-qualified semantic_search tool")
 			}
 		})
 	}
@@ -184,7 +221,7 @@ func TestEvaluateToolCall_BashNonSearchSilentAllow(t *testing.T) {
 				ToolName: "Bash",
 				Input:    map[string]any{"command": cmd},
 			}
-			result := evaluateToolCall(input, "lumen")
+			result := evaluateToolCall(input, "lumen", "lumen")
 			if result != nil {
 				t.Errorf("expected nil for non-search bash command %q, got suggestion", cmd)
 			}
@@ -196,7 +233,7 @@ func TestPreToolUseOutputJSON(t *testing.T) {
 	result := evaluateToolCall(preToolUseInput{
 		ToolName: "Grep",
 		Input:    map[string]any{"pattern": "error handling middleware"},
-	}, "lumen")
+	}, "lumen", "lumen")
 	if result == nil {
 		t.Fatal("expected non-nil result")
 	}
@@ -432,7 +469,9 @@ func TestGenerateSessionContextInternal_NonGitUsesParentIndex(t *testing.T) {
 func TestHookOutputJSON(t *testing.T) {
 	// Use the internal version with a no-op bgIndexer — same fork-bomb reason
 	// as in TestGenerateSessionContext_NoIndex.
-	content := generateSessionContextInternal("/nonexistent/path",
+	content := generateSessionContextInternalWithDirective(
+		sessionStartDirective(hookHostClaude, "lumen", "lumen"),
+		"/nonexistent/path",
 		func(_, _ string) string { return "" },
 		func(_ string) {},
 	)
@@ -461,14 +500,14 @@ func TestHookOutputJSON(t *testing.T) {
 		t.Errorf("hookEventName = %v, want SessionStart", hso["hookEventName"])
 	}
 	ctx, ok := hso["additionalContext"].(string)
-	if !ok || !strings.Contains(ctx, "mcp__lumen__semantic_search") {
-		t.Error("additionalContext should contain tool reference")
+	if !ok || !strings.Contains(ctx, "mcp__plugin_lumen_lumen__semantic_search") {
+		t.Error("additionalContext should contain the plugin-qualified tool reference")
 	}
 }
 
 func TestSessionStartOutputCursorJSON(t *testing.T) {
 	content := generateSessionContextInternalWithDirective(
-		sessionStartDirective(hookHostCursor, "lumen"),
+		sessionStartDirective(hookHostCursor, "lumen", "lumen"),
 		"/nonexistent/path",
 		func(_, _ string) string { return "" },
 		func(_ string) {},
diff --git a/hooks/hooks.json b/hooks/hooks.json
index 21aea78a..410c2f2b 100644
--- a/hooks/hooks.json
+++ b/hooks/hooks.json
@@ -6,7 +6,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook session-start lumen --host claude"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook session-start lumen --host claude --plugin-name lumen"
           }
         ]
       }
@@ -17,7 +17,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook pre-tool-use lumen"
+            "command": "\"${CLAUDE_PLUGIN_ROOT}/scripts/run\" hook pre-tool-use lumen --plugin-name lumen"
           }
         ]
       }