error-classification

A software vocabulary and decision guide for distinguishing errors, defects, faults, failures, incidents, bugs, and exceptions.

In plain words
What is it for?
Use it to classify abnormal software states and choose handling such as validation, retries, alerts, or defect fixes.
Why use it?
It prevents different kinds of problems from being treated as if they needed the same response.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/amadeus-dlc/amadeus/error-classification
Any agent
npx skills add amadeus-dlc/amadeus --skill error-classification
Clone the repo
git clone --depth 1 https://github.com/amadeus-dlc/amadeus

Made for: Claude Code, Codex.

Per session 66 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 367 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00066 $0.00367
Opus 5 $0.00033 $0.00183
Sonnet 5 $0.00013 $0.00073
Haiku 4.5 $0.00007 $0.00037

Measured 2d ago against content hash 868640d9e388, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

error-classification scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

amadeus/spaces/default/knowledge/amadeus-shared/software-design/error-classification/SKILL.md · 44 lines

What it actually says

Error Classification

Classify abnormal states before designing their handling. Different words imply different interventions.

Working Vocabulary

  • Error: a human or system mistake in reasoning, input, configuration, or operation.

  • Defect: a flaw in an artifact such as code, requirements, tests, or documentation.

  • Bug: an informal report or label for a defect, fault, or failure; clarify which precise category is meant before choosing a response.

  • Fault: an incorrect internal state or latent condition that can cause failure.

  • Failure: externally observable deviation from expected service.

  • Incident: an operational event requiring response.

  • Exception: a language/runtime control mechanism or signal, not a domain classification by itself; classify the condition it represents.

Workflow

  1. Describe what was observed and by whom.

  2. Separate external failure from internal fault and underlying defect.

  3. Identify whether the condition is recoverable, retryable, user-correctable, or fatal.

  4. Choose handling: validation error, typed domain error, exception, retry, circuit breaker, alert, or defect fix.

Detailed Reference

For non-trivial implementation, review, or refactoring work, read references/details.md before giving final guidance. It contains the detailed rules, examples, smells, and migration notes that do not belong in the short invocation body.

Output

Return the classification chain, handling strategy, tests to add, and terms the team should use consistently.

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 44 lines · 66 tokens per session scan A 868640d9e388

Subscribe to this mod's changes

error-classification is a skill published in the GitHub repository amadeus-dlc/amadeus (8 stars, last pushed 12d ago), licensed Apache-2.0. It adds 66 tokens to every session and 367 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.