Garbled skill data, when using multi-line syntax #12313
Description
Bug Description
User-defined skill descriptions that use YAML multi-line literal blocks (| or >) are displayed as "| (user)" instead of showing the actual description text.
Steps to Reproduce
- Create a skill with multi-line description in
~/.claude/skills/example/SKILL.md:
---
name: example-skill
description: |
This is a multi-line description.
It should display properly.
---- Run
claudeand invoke the Skill tool - Observe the skill description shows as:
| (user)
Expected Behavior
The full description text should be displayed:
This is a multi-line description. It should display properly. (user)
Root Cause
The frontmatter parser function qF() (line 286209 in bundled cli.js v2.0.51) is a hand-rolled YAML parser that doesn't handle multi-line literal blocks. It only parses single-line key: value pairs.
When it encounters description: |, it captures only the "|" character as the value, ignoring the subsequent indented lines.
Proposed Fix
Minimal patch to add multi-line block support while maintaining the existing minimalist parser approach:
function qF(A) {
let Q = /^---\s*\n([\s\S]*?)---\s*\n?/,
B = A.match(Q);
if (!B) return {
frontmatter: {},
content: A
};
let G = B[1] || "",
Z = A.slice(B[0].length),
I = {},
Y = G.split(`
`);
let blockKey = null,
blockLines = [];
for (let J of Y) {
if (blockKey !== null) {
if (!J.match(/^\S/)) {
blockLines.push(J.trim());
continue;
} else {
I[blockKey] = blockLines.join("\n");
blockKey = null;
blockLines = [];
}
}
let W = J.indexOf(":");
if (W > 0) {
let X = J.slice(0, W).trim(),
F = J.slice(W + 1).trim();
if (X) {
if (F === "|" || F === ">") {
blockKey = X;
blockLines = [];
continue;
}
let V = F.replace(/^["']|["']$/g, "");
I[X] = V
}
}
}
if (blockKey !== null) I[blockKey] = blockLines.join("\n");
return {
frontmatter: I,
content: Z
}
}Changes:
- Added
blockKeyandblockLinesstate to track multi-line blocks - Detect
|or>as value and enter block collection mode - Collect subsequent indented lines until non-indented line found
- Join collected lines and assign to the key
Tested with:
- Multi-line literal blocks (
|) - Folded blocks (
>) - Single-line values (backward compatible)
- Mixed frontmatter with both single and multi-line values
Version
@anthropic-ai/claude-code: 2.0.51- Node: v18+
Alternative Solution
Replace the hand-rolled parser with a proper YAML library like js-yaml, though this adds a dependency.