Lists multiple concrete actions: 'Translates cryptic runtime error messages and stack traces into understandable explanations', 'pointing to the concrete line at fault', and 'the most likely fix'. These are specific, actionable capabilities.

Clearly answers both what (translates errors, points to faulty line, suggests fix) AND when with explicit 'Use when' clause covering three distinct trigger scenarios: pasted errors, deep stack traces, and misleading error messages.

Includes natural keywords users would say: 'error messages', 'stack traces', 'error they don't understand', 'stack trace is deep'. These match how users naturally describe debugging problems.

Has a clear niche focused specifically on error interpretation and debugging. The triggers are distinct ('cryptic runtime error', 'stack traces', 'error message misleads') and unlikely to conflict with general coding or documentation skills.

Every section earns its place. No explanation of what exceptions are or how stack traces work in general—assumes Claude knows. Tables are dense and scannable. The 'Do not' section prevents common verbose anti-patterns.

Provides concrete translation templates, a fully worked example with real stack trace, specific diagnostic commands, and a structured output format. The error-to-cause mapping table is immediately usable.

Clear sequence: read stack in correct direction → identify user code frame → check if error lies → unwrap chained exceptions → apply template → output structured explanation. The worked example demonstrates the full workflow.

Well-organized single file appropriate for this skill's scope. Tables provide quick reference, worked example provides depth, edge cases handle special situations. No need for external files given the focused nature of the task.