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pr-review-toolkit: silent-failure-hunter agent has invalid YAML frontmatter, loads with empty metadata #86748
Description
Summary
plugins/pr-review-toolkit/agents/silent-failure-hunter.md has invalid YAML frontmatter. The agent loads with empty metadata — every frontmatter field (name, description, model, color) is silently dropped at runtime.
The other 5 agents in the same plugin parse fine.
Root cause
The description value is unquoted and contains embedded : sequences inside the example dialogue:
Daisy: "I've added error handling to the API client. Can you review it?"
Assistant: "Let me use the silent-failure-hunter agent..."
In YAML, key: value inside an unquoted scalar is parsed as a nested mapping, which is invalid in that position.
Reproduction
git clone --depth 1 https://github.com/anthropics/claude-code
python3 - <<'PY'
import re, yaml
p = "claude-code/plugins/pr-review-toolkit/agents/silent-failure-hunter.md"
fm = re.match(r'^---\n(.*?)\n---\n', open(p, encoding='utf-8').read(), re.S).group(1)
yaml.safe_load(fm)
PYResult:
yaml.scanner.ScannerError: mapping values are not allowed here
in "<unicode string>", line 2, column 393
claude plugin validate reports the same, and states the runtime consequence explicitly:
❯ frontmatter: YAML frontmatter failed to parse: YAML Parse error: Unexpected token.
At runtime this agent loads with empty metadata (all frontmatter fields silently dropped).
Impact
The agent cannot be selected by description-based routing, since its description never reaches the model. Users installing pr-review-toolkit get 5 working agents out of 6, with no error surfaced unless they run claude plugin validate manually.
Suggested fix
Quote the description as a YAML block scalar, matching what code-simplifier.md in the same plugin already does:
description: |
Use this agent when reviewing code changes in a pull request to identify
silent failures, inadequate error handling, and inappropriate fallback behavior.
...Environment
- Found via
claude plugin validateon an installed copy, then confirmed against a fresh clone ofmain - Also affects the mirrored copy distributed through the
claude-plugins-officialmarketplace
Activity
bcherny commentedon Aug 17, 2026
Confirmed. The frontmatter of
plugins/pr-review-toolkit/agents/silent-failure-hunter.mdonmainfails to parse as YAML — a strict parser reportsNested mappings are not allowed in compact mappings (line 3, column 14), because the unquoteddescription:value contains:sequences inside the example dialogue (Daisy: "…"). Claude Code's frontmatter reader falls back to empty metadata, which is exactly the "loads with empty metadata / every field dropped" behaviour you saw; the other agents in the plugin parse fine.Fix is to quote (or block-scalar
|) the description. We'll get that landed in the plugin.🤖 Generated with Claude Code
github-actions commentedon Sep 20, 2026
Closing for now — inactive for too long. Please open a new issue if this is still relevant.
marcindulak commentedon Sep 20, 2026
This issue was incorrectly closed by the github-actions bot, despite having reproduction steps (though no Claude version as the issue is about a plugin). This bot behavior is tracked in #87647. Consider upvoting that issue for visibilty, maybe the bot behavior gets fixed.