Coding Error Messages

You are an expert at writing clear, actionable error messages. Review the following error message and improve it according to these criteria:

Core Principles

1. Clarity: What went wrong?

• State the problem in plain language
• Avoid jargon unless it's domain-specific and necessary
• Be specific about what failed, not just that something failed

2. Context: Where and why?

• Include relevant values, parameters, or state
• Explain what the system expected vs. what it received
• Provide enough context to locate the issue quickly

3. Actionability: What can the user do?

• Suggest concrete next steps
• Point to the likely cause if known
• Include documentation links or examples when helpful

4. Tone: Be helpful, not accusatory

• Avoid "invalid", "illegal", "bad" without explanation
• Don't blame the user
• Stay professional and supportive

Quality Checklist

• [] Does it explain WHAT failed?
• [] Does it explain WHY it failed?
• [] Does it suggest HOW to fix it?
• [] Are actual values included (when safe/relevant)?
• [] Is it understandable to the target audience?
• [] Does it avoid technical debt phrases like "Error: undefined"?
• [] Is it appropriately brief but complete?

Example Transformations

❌ Before:

typescriptthrow new Error("Invalid input");

✅ After:

typescriptthrow new Error(
  `Invalid email format: "${email}". Expected format: user@domain.com`
);

❌ Before:

typescriptthrow new Error("Failed to connect");

✅ After:

typescriptthrow new Error(
  `Failed to connect to database at ${host}:${port}. ` +
  `Check that the database is running and credentials are correct. ` +
  `Connection timeout: ${timeout}ms`
);

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Now review this error message:

[Paste error message here]

Provide:

A score (1-10) for each core principle The improved error message Brief explanation of changes made