# Python Errors Reliability

> |-

- **Type:** Skill
- **Install:** `agentstack add skill-ahgraber-skills-python-errors-reliability`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [ahgraber](https://agentstack.voostack.com/s/ahgraber)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** CC0-1.0
- **Upstream author:** [ahgraber](https://github.com/ahgraber)
- **Source:** https://github.com/ahgraber/skills/tree/main/skills/python-errors-reliability

## Install

```sh
agentstack add skill-ahgraber-skills-python-errors-reliability
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Python Errors and Reliability

## Overview

Design errors so callers can act and operators can diagnose quickly.
Treat these recommendations as preferred defaults — when a default conflicts with project constraints, suggest a better-fit alternative and call out tradeoffs and compensating controls.

## When to Use

- Implementing or reviewing timeout, deadline, or retry logic.
- Translating exceptions across layer boundaries (e.g., infra → domain).
- Classifying failures as retryable vs. permanent.
- Adding idempotency guarantees to retried writes.
- Diagnosing swallowed exceptions or silent failures in existing code.

**When NOT to use:**

- Pure data-transformation code with no I/O or failure modes.
- Simple validation that raises immediately with no translation needed.
- Performance tuning unrelated to failure handling (see `python-concurrency-performance`).

## Quick Reference

- Preserve cause chains at translation boundaries.
- Catch only what can be handled.
- Keep timeout/deadline policy explicit.
- Keep retry policy explicit and bounded.
- Classify retryable vs. permanent failures with explicit policy data.
- Keep idempotency expectations explicit for retried writes.

## Common Mistakes

- **Swallowing exceptions** — bare `except: pass` or `except Exception` with no logging loses diagnostic context.
- **Unbounded retries** — retrying without a maximum count or total deadline leads to cascading failures and resource exhaustion.
- **Dropping the cause chain** — raising a new exception without `from original` discards the root cause operators need for diagnosis.
- **Treating all errors as retryable** — retrying a 400 Bad Request or a validation error wastes resources and delays the real fix.
- **Implicit timeouts** — relying on library defaults (or no timeout at all) produces unpredictable latency under failure conditions.

## Scope Note

- Treat these recommendations as preferred defaults for common cases, not universal rules.
- If a default conflicts with project constraints or worsens the outcome, suggest a better-fit alternative and explain why it is better for this case.
- When deviating, call out tradeoffs and compensating controls (tests, observability, migration, rollback).

## Invocation Notice

- Inform the user when this skill is being invoked by name: `python-design-modularity`.

## References

- `references/error-strategy.md`
- `references/retryability-classification.md`
- `references/retries-timeouts.md`

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [ahgraber](https://github.com/ahgraber)
- **Source:** [ahgraber/skills](https://github.com/ahgraber/skills)
- **License:** CC0-1.0

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-ahgraber-skills-python-errors-reliability
- Seller: https://agentstack.voostack.com/s/ahgraber
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.