diff --git a/src/mcp/mcp.c b/src/mcp/mcp.c
index 807cc42da..a681a7911 100644
--- a/src/mcp/mcp.c
+++ b/src/mcp/mcp.c
@@ -2824,6 +2824,23 @@ static int mcp_get_current_schema(cbm_store_t *store, const char *project,
                       : cbm_store_get_schema_counts(store, project, out);
 }
 
+/* Copy only the selected project name into caller-owned stack storage. This is
+ * not a database/graph snapshot: the bounded copy keeps the name valid if
+ * resolve_store closes a replaced database and frees current_project. */
+static const char *mcp_copy_schema_project_name(cbm_mcp_server_t *srv, char *out, size_t out_size) {
+    if (!srv || !out || out_size == 0) {
+        return NULL;
+    }
+    const char *source = srv->current_project && srv->current_project[0]
+                             ? srv->current_project
+                             : (srv->session_project[0] ? srv->session_project : NULL);
+    if (!source) {
+        return NULL;
+    }
+    int written = snprintf(out, out_size, "%s", source);
+    return written >= 0 && (size_t)written < out_size ? out : NULL;
+}
+
 /* Build the query_graph docstring once per published graph state. It belongs in
  * MCP tools/list so reconnects and relists can restore actionable schema after
  * context compaction; it must never be appended to tools/call results. Full
@@ -2867,16 +2884,7 @@ static char *build_query_graph_tool_description(cbm_mcp_server_t *srv,
      * next use). Passing the live pointer through would free the very
      * string resolve_store is still reading (use-after-free). */
     char project_buf[CBM_SZ_256];
-    const char *project = NULL;
-    if (srv) {
-        const char *src = srv->current_project && srv->current_project[0]
-                              ? srv->current_project
-                              : (srv->session_project[0] ? srv->session_project : NULL);
-        if (src) {
-            snprintf(project_buf, sizeof(project_buf), "%s", src);
-            project = project_buf;
-        }
-    }
+    const char *project = mcp_copy_schema_project_name(srv, project_buf, sizeof(project_buf));
     /* Lazily resolve the project's real store rather than trusting
      * srv->store as-is: on the very first tools/list of a fresh session
      * (before any tool call has resolved a project), srv->store is still
@@ -2953,6 +2961,18 @@ static const char *query_graph_tool_description(cbm_mcp_server_t *srv,
     if (!srv) {
         return tool_def->description;
     }
+    if (srv->query_graph_tool_description) {
+        /* A sibling CLI/MCP/HTTP worker cannot flip this process's stale bit.
+         * Probe the cached query-only store's stable file identity on each
+         * relist so an atomic database replacement invalidates the inline
+         * schema before it is served. resolve_store is O(1) on the unchanged
+         * fast path and closes/reopens only on this request-owning thread. */
+        char project_buf[CBM_SZ_256];
+        const char *project = mcp_copy_schema_project_name(srv, project_buf, sizeof(project_buf));
+        if (project) {
+            (void)resolve_store(srv, project);
+        }
+    }
     if (atomic_exchange(&srv->query_graph_tool_description_stale, false)) {
         free(srv->query_graph_tool_description);
         srv->query_graph_tool_description = NULL;
@@ -3687,6 +3707,10 @@ static cbm_store_t *resolve_store(cbm_mcp_server_t *srv, const char *project) {
         if (!cbm_store_backing_file_replaced(srv->store)) {
             return srv->store;
         }
+        /* The same identity mismatch that invalidates query rows also
+         * invalidates cached tools/list schema. This is request-thread-owned;
+         * sibling liveness is never inferred and no cross-thread free occurs. */
+        atomic_store(&srv->query_graph_tool_description_stale, true);
         if (srv->owns_store) {
             cbm_store_close(srv->store);
         }
diff --git a/tests/test_mcp.c b/tests/test_mcp.c
index 41a07fddc..c24cd7014 100644
--- a/tests/test_mcp.c
+++ b/tests/test_mcp.c
@@ -210,7 +210,7 @@ static int mcp_project_db_path(char *out, size_t out_sz, const char *cache,
 }
 
 static bool mcp_create_generation_db(const char *db_path, const char *project,
-                                     const char *node_name) {
+                                     const char *node_label, const char *node_name) {
     cbm_store_t *store = cbm_store_open_path(db_path);
     if (!store) {
         return false;
@@ -218,7 +218,7 @@ static bool mcp_create_generation_db(const char *db_path, const char *project,
     char qualified_name[CBM_PATH_MAX];
     int n = snprintf(qualified_name, sizeof(qualified_name), "%s.%s", project, node_name);
     cbm_node_t node = {.project = project,
-                       .label = "Function",
+                       .label = node_label,
                        .name = node_name,
                        .qualified_name = qualified_name,
                        .file_path = "src/generation.c",
@@ -11626,7 +11626,7 @@ TEST(watcher_publication_reopens_cached_store_generation) {
     char next_path[CBM_PATH_MAX];
     ASSERT_EQ(mcp_project_db_path(live_path, sizeof(live_path), cache, project), CBM_STORE_OK);
     snprintf(next_path, sizeof(next_path), "%s/next-generation.db", cache);
-    ASSERT_TRUE(mcp_create_generation_db(live_path, project, "BeforePublication"));
+    ASSERT_TRUE(mcp_create_generation_db(live_path, project, "Function", "BeforePublication"));
 
     cbm_mcp_server_t *srv = cbm_mcp_server_new(NULL);
     ASSERT_NOT_NULL(srv);
@@ -11638,7 +11638,7 @@ TEST(watcher_publication_reopens_cached_store_generation) {
     ASSERT_NOT_NULL(strstr(before, "BeforePublication"));
     free(before);
 
-    ASSERT_TRUE(mcp_create_generation_db(next_path, project, "AfterPublication"));
+    ASSERT_TRUE(mcp_create_generation_db(next_path, project, "Function", "AfterPublication"));
     cbm_remove_db_sidecars(live_path);
     ASSERT_EQ(cbm_replace_file(next_path, live_path), 0);
 
@@ -11669,7 +11669,8 @@ TEST(external_process_publication_reopens_cached_store_generation) {
     char next_path[CBM_PATH_MAX];
     ASSERT_EQ(mcp_project_db_path(live_path, sizeof(live_path), cache, project), CBM_STORE_OK);
     snprintf(next_path, sizeof(next_path), "%s/external-next-generation.db", cache);
-    ASSERT_TRUE(mcp_create_generation_db(live_path, project, "BeforeExternalPublication"));
+    ASSERT_TRUE(mcp_create_generation_db(live_path, project, "BeforeExternalLabel",
+                                         "BeforeExternalPublication"));
 
     cbm_mcp_server_t *srv = cbm_mcp_server_new(NULL);
     ASSERT_NOT_NULL(srv);
@@ -11681,12 +11682,26 @@ TEST(external_process_publication_reopens_cached_store_generation) {
     ASSERT_NOT_NULL(strstr(before, "BeforeExternalPublication"));
     free(before);
 
-    ASSERT_TRUE(mcp_create_generation_db(next_path, project, "AfterExternalPublication"));
+    char *before_list = cbm_mcp_server_handle(
+        srv, "{\"jsonrpc\":\"2.0\",\"id\":201,\"method\":\"tools/list\",\"params\":{}}");
+    ASSERT_NOT_NULL(before_list);
+    ASSERT_NOT_NULL(strstr(before_list, "BeforeExternalLabel"));
+    free(before_list);
+
+    ASSERT_TRUE(mcp_create_generation_db(next_path, project, "AfterExternalLabel",
+                                         "AfterExternalPublication"));
     cbm_remove_db_sidecars(live_path);
     ASSERT_EQ(cbm_replace_file(next_path, live_path), 0);
 
     /* Deliberately no cbm_mcp_server_notify_index_published(): a sibling
      * process has no access to this server's in-memory notification flag. */
+    char *after_list = cbm_mcp_server_handle(
+        srv, "{\"jsonrpc\":\"2.0\",\"id\":202,\"method\":\"tools/list\",\"params\":{}}");
+    ASSERT_NOT_NULL(after_list);
+    ASSERT_NOT_NULL(strstr(after_list, "AfterExternalLabel"));
+    ASSERT_NULL(strstr(after_list, "BeforeExternalLabel"));
+    free(after_list);
+
     char *after =
         cbm_mcp_handle_tool(srv, "search_graph",
                             "{\"project\":\"external-generation-project\","