---
id: "claim-single-line-description"
type: "claim"
source_timestamps: ["10:25:00", "10:35:00"]
tags: ["technical-constraint", "claude"]
related: ["concept-description-routing-signal", "action-single-line-descriptions", "entity-product-claude"]
confidence: "high"
testable: true
speakers: ["Nate B. Jones"]
sources: ["s43-file-format-agreement"]
sourceVaultSlug: "s43-file-format-agreement"
originDay: 43
---
# Multi-line descriptions silently break Claude skills

## Claim

If a code formatter or user breaks the `description` field in `skill.md` across multiple lines, [[entity-product-claude-d43]] silently fails to read anything past the first line — effectively breaking the routing signal for that skill.

## Why It's Insidious

The failure is **silent**: the skill simply stops triggering, with no error message. Authors believe the description is verbose and informative, but the agent only ever sees the first line.

## Confidence: High · Testable: Yes

This is a specific, reproducible technical constraint in Claude's current implementation.

## Validation (Enrichment)

Partially validated. Anthropic's Claude documentation specifies YAML frontmatter parsing for skills, where multi-line descriptions in `description:` may truncate if not properly formatted (e.g., via quoted strings or YAML folding). Community reports confirm parsing quirks in early 2024 releases.

## Action

See [[action-single-line-descriptions]] — keep the `description` field on a single line, or use proper YAML folded/literal scalar syntax if you need multi-line content.

## Related

- [[concept-description-routing-signal]]