diff --git a/src/common/utils/tools/taskToolTypeGuards.ts b/src/common/utils/tools/taskToolTypeGuards.ts
deleted file mode 100644
index f69577f6bd..0000000000
--- a/src/common/utils/tools/taskToolTypeGuards.ts
+++ /dev/null
@@ -1,47 +0,0 @@
-// Shared type guards for tool argument shapes.
-//
-// NOTE: The `task` tool is agent-only today, but older chat histories may contain
-// legacy `task(kind="bash")` calls. Keep these helpers in `src/common` so both the
-// desktop and mobile renderers can detect those shapes without importing node-only code.
-
-export interface TaskBashArgs {
-  kind: "bash";
-  script: string;
-  timeout_secs: number;
-  run_in_background?: boolean;
-  display_name?: string;
-}
-
-export function isTaskBashArgsFromUnknown(value: unknown): value is TaskBashArgs {
-  if (!value || typeof value !== "object") {
-    return false;
-  }
-
-  const args = value as Partial<TaskBashArgs>;
-
-  if (args.kind !== "bash") {
-    return false;
-  }
-
-  if (typeof args.script !== "string" || args.script.trim().length === 0) {
-    return false;
-  }
-
-  if (typeof args.timeout_secs !== "number" || !Number.isFinite(args.timeout_secs)) {
-    return false;
-  }
-
-  if (args.run_in_background !== undefined && typeof args.run_in_background !== "boolean") {
-    return false;
-  }
-
-  if (args.display_name !== undefined && typeof args.display_name !== "string") {
-    return false;
-  }
-
-  return true;
-}
-
-export function isTaskBashArgs(value: unknown): value is TaskBashArgs {
-  return isTaskBashArgsFromUnknown(value);
-}
diff --git a/src/node/services/tools/taskId.ts b/src/node/services/tools/taskId.ts
index 4466e1e3ff..7bdf0e5fb6 100644
--- a/src/node/services/tools/taskId.ts
+++ b/src/node/services/tools/taskId.ts
@@ -18,7 +18,3 @@ export function fromBashTaskId(taskId: string): string | null {
   const processId = taskId.slice(BASH_TASK_ID_PREFIX.length).trim();
   return processId.length > 0 ? processId : null;
 }
-
-export function isBashTaskId(taskId: string): boolean {
-  return fromBashTaskId(taskId) !== null;
-}