Quote argument-hint in SKILL.md so it parses as a string

[thejesh23]

Bug

SKILL.md frontmatter currently declares:

argument-hint: [image path and/or description of the 3D model]

In YAML, an unquoted [...] is a flow sequence (a list), not a string. That line parses to:

['image path and/or description of the 3D model']

GitHub Copilot CLI 1.0.65 (which reads Claude-style skills / prompts) requires argument-hint to be a string and errors out when it receives a list. Claude Code has historically been permissive here, but the same latent typing issue is tracked in anthropics/claude-code#22161, so tightening this to a string is safe there too.

Fix

Wrap the value in double quotes so YAML parses it as a scalar string:

argument-hint: "[image path and/or description of the 3D model]"

The rendered hint the user sees is identical ([image path and/or description of the 3D model]); only the YAML type changes from list to string.

Test plan

• python3 -c "import yaml; d=yaml.safe_load(open('SKILL.md').read().split('---')[1]); assert isinstance(d['argument-hint'], str)" passes
• /render <prompt> still shows the hint in Claude Code exactly as before
• Skill loads without a type error under Copilot CLI 1.0.65

[thejesh23]

Tracking issue: #7 — captures the bug diagnosis and reproducer separately for anyone searching the repo who lands there before this PR.