The Blind Spot Was the Rule I Wrote to Avoid False Positives

Description and use

The configuration linter missed a syntax error because a rule to avoid false positives incorrectly excluded checking the tools field. After updating the rule and correcting the config, the linter now flags undocumented patterns.

Problem

A linter for a configuration format silently missed a syntax error because a rule to avoid false positives incorrectly excluded checking the tools field.

Outcome

The linter now correctly identifies undocumented syntax errors, reducing silent failures and improving configuration reliability.

Workflow

• Run linter on all configuration files
• Identify files with no reported issues
• Manually inspect files for hidden errors
• Find tools: * in four files
• Update linter rule to warn on undocumented patterns
• Remove tools: * and omit field instead
• Add test fixtures for valid and invalid patterns
• Run full test suite to confirm zero findings

Evidence

tools: * is not a documented pattern. Omit tools to inherit every tool available to subagents.

Source

The linter passed
product/kit No problems (5 files checked) product/oss No problems (4 files checked)