# Error Messages

> Expert skill for designing and implementing high-quality compiler error messages

- Skill: `a5c-ai/error-messages` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add a5c-ai/error-messages`
- Raw SKILL.md: https://api.skillmd.com/api/skills/a5c-ai/error-messages/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: a5c-ai (https://skillmd.com/u/a5c-ai)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/a5c-ai/error-messages

---


# Error Messages Skill

## Overview

Expert skill for designing and implementing high-quality compiler error messages.

## Capabilities

- Design clear, actionable error message templates
- Implement source context display with underlines
- Generate fix suggestions and quick fixes
- Handle error cascades and suppression
- Implement multi-span error annotations
- Support machine-readable error output (JSON)
- Implement color/styled terminal output
- Design error recovery strategies for better diagnostics

## Target Processes

- error-message-enhancement.js
- parser-development.js
- type-system-implementation.js
- semantic-analysis.js
- lsp-server-implementation.js

## Dependencies

Elm/Rust error message guidelines

## Usage Guidelines

1. **Clarity**: Make error messages clear and actionable
2. **Context**: Show relevant source code context with precise location
3. **Suggestions**: Provide fix suggestions when possible
4. **Cascades**: Suppress cascading errors to avoid overwhelming users
5. **Machine-Readable**: Support JSON output for tooling integration

## Output Schema

```json
{
  "type": "object",
  "properties": {
    "errorFormat": {
      "type": "string",
      "enum": ["human", "json", "sarif"]
    },
    "features": {
      "type": "array",
      "items": { "type": "string" }
    },
    "colorSupport": { "type": "boolean" },
    "generatedFiles": {
      "type": "array",
      "items": { "type": "string" }
    }
  }
}
```