VS Code skill frontmatter validator: typo in 'user-invokable' and incomplete field list
Status Fixed / completed
Reported on v2.1.50
Maintainer reply None cached
Activity 4 comments · opened Feb 21, 2026 · closed Feb 21, 2026
Bug
The VS Code extension's SKILL.md frontmatter validator has two issues:
1. Typo: user-invokable instead of user-invocable
When using an unsupported attribute like user_invocable, the error message suggests user-invokable (with k):
Attribute 'user_invocable' is not supported in skill files.
Supported: argument-hint, compatibility, description, disable-model-invocation, license, metadata, name, user-invokable.However, the runtime reads user-invocable (with c):
// from wmT() in the Claude Code binary (v2.1.50)
h = O["user-invocable"] === undefined ? true : aFR(O["user-invocable"])The official docs also use user-invocable (with c).
Following the VS Code suggestion leads to a field that the runtime silently ignores.
2. Incomplete field list
The validator only accepts 8 fields:argument-hint, compatibility, description, disable-model-invocation, license, metadata, name, user-invokable
The runtime actually reads these additional fields (verified in binary v2.1.50):
allowed-tools(documented)model(documented)context(documented)agent(documented)hooks(documented)argumentswhen_to_useversionpaths(conditional activation by glob patterns)
Using any of these valid fields triggers a false-positive validation error in VS Code.
Environment
- Claude Code: 2.1.50
- VS Code extension: anthropic.claude-code-2.0.75-darwin-arm64
- OS: macOS (Darwin, arm64)
4 Comments
Found 3 possible duplicate issues:
This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
Worth noting: many of the official/marketplace skills from Anthropic themselves ship with frontmatter that doesn't match the spec:
session-checkpoint: uses>-block scalar for description (silently ignored per #9817)vercel-composition-patterns: plain multi-line description (same issue)pgvector-semantic-search:|block scalar descriptionmemory-fabric: 10 non-standard fields (license,compatibility,version,author,tags,user-invocable,allowed-tools,complexity,metadata,context)rag-retrieval: 9 non-standard fields (similar set)algorithmic-art,canvas-design,frontend-design,pdf,skill-creator:licensefieldseo-audit,vercel-react-best-practices,web-design-guidelines:metadatafieldreact-doctor:versionfieldIf official skills don't follow the spec, users have no reliable reference for correct formatting. The validator should either accept all fields the runtime reads, or the official skills should be fixed to match the spec.
Closing as duplicate of #27009, #23723, and #26795 which cover the same validator issues (typo in user-invokable, incomplete field list). Added our findings about official skills having the same problems as a comment for reference.
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