Error: Invalid frontmatter when importing Claude commands

[KrustyHack]

Ay,

[rulesync 12:04:30 PM]  ERROR  Error: Invalid frontmatter in /xxx/.claude/commands/save-requirement.md: Zod raw error: [{"expected":"string","code":"invalid_type","path":["argument-hint"],"message":"Invalid input: expected string, received array"}]

When trying to do rulesync import --targets claudecode --features rules,mcp,commands,subage nts

Example in one of my .claude command file :

---
description: Break down a requirement into AI-generated tasks
allowed-tools: >-
  Bash(braingrid:*), Bash(git:*), Bash(npm:*), Read, Grep, Glob,
  Skill(braingrid-cli)
argument-hint: [requirement-id]
---

Expected : [] format should work when importing commands with rulesync.

[cm-dyoshikawa]

@KrustyHack Thank you. It seems a bug.