fix: auto-truncate question option labels exceeding 30 characters

When AI generates AskUserQuestion tool calls with option labels longer
than 30 characters, opencode validation rejects them with "too_big" error.

This fix adds a pre-tool-use hook that automatically truncates labels
to 30 characters (with "..." suffix) before the validation occurs.

Fixes the error:
"The question tool was called with invalid arguments: expected string
to have <=30 characters"

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/hooks/index.ts

@@ -30,3 +30,4 @@ export { createTaskResumeInfoHook } from "./task-resume-info";
 export { createStartWorkHook } from "./start-work";
 export { createAtlasHook } from "./atlas";
 export { createDelegateTaskRetryHook } from "./delegate-task-retry";
+export { createQuestionLabelTruncatorHook } from "./question-label-truncator";

src/hooks/question-label-truncator/index.ts

@@ -0,0 +1,63 @@
+import type { Plugin } from "@opencode-ai/plugin";
+
+const MAX_LABEL_LENGTH = 30;
+
+interface QuestionOption {
+  label: string;
+  description?: string;
+}
+
+interface Question {
+  question: string;
+  header?: string;
+  options: QuestionOption[];
+  multiSelect?: boolean;
+}
+
+interface AskUserQuestionArgs {
+  questions: Question[];
+}
+
+function truncateLabel(label: string, maxLength: number = MAX_LABEL_LENGTH): string {
+  if (label.length <= maxLength) {
+    return label;
+  }
+  return label.substring(0, maxLength - 3) + "...";
+}
+
+function truncateQuestionLabels(args: AskUserQuestionArgs): AskUserQuestionArgs {
+  if (!args.questions || !Array.isArray(args.questions)) {
+    return args;
+  }
+
+  return {
+    ...args,
+    questions: args.questions.map((question) => ({
+      ...question,
+      options: question.options?.map((option) => ({
+        ...option,
+        label: truncateLabel(option.label),
+      })) ?? [],
+    })),
+  };
+}
+
+export function createQuestionLabelTruncatorHook(): Pick<
+  Plugin,
+  "tool.execute.before"
+> {
+  return {
+    "tool.execute.before": async (input, output) => {
+      const toolName = input.tool?.toLowerCase();
+
+      if (toolName === "askuserquestion" || toolName === "ask_user_question") {
+        const args = output.args as AskUserQuestionArgs | undefined;
+
+        if (args?.questions) {
+          const truncatedArgs = truncateQuestionLabels(args);
+          Object.assign(output.args as object, truncatedArgs);
+        }
+      }
+    },
+  };
+}

src/index.ts

@@ -31,6 +31,7 @@ import {
   createStartWorkHook,
   createAtlasHook,
   createPrometheusMdOnlyHook,
+  createQuestionLabelTruncatorHook,
 } from "./hooks";
 import {
   contextCollector,
@@ -203,6 +204,8 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     ? createPrometheusMdOnlyHook(ctx)
     : null;
 
+  const questionLabelTruncator = createQuestionLabelTruncatorHook();
+
   const taskResumeInfo = createTaskResumeInfoHook();
 
   const backgroundManager = new BackgroundManager(ctx, pluginConfig.background_task);
@@ -484,6 +487,7 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
     },
 
     "tool.execute.before": async (input, output) => {
+      await questionLabelTruncator["tool.execute.before"]?.(input, output);
       await claudeCodeHooks["tool.execute.before"](input, output);
       await nonInteractiveEnv?.["tool.execute.before"](input, output);
       await commentChecker?.["tool.execute.before"](input, output);