rings: Agent for Claude Code

.claude/agents/impl-error-handling.md

impl-error-handling is an agent for Claude Code from pinecone-io/rings. It costs 46 tokens per session (469 once invoked), scanned A, original, Apache-2.0.

A reviewer for implementation plans in Rust, focused on how programs classify, pass along, and explain errors. It considers general-purpose errors as well as typed errors that callers can handle differently.

In plain words
What is it for?
Use it to review error types, anyhow versus typed errors, error propagation, context wrapping, user-facing messages, and handling for quota, authentication, and unknown failures.
Why use it?
It helps prevent errors from being hidden, misclassified, mapped to the wrong exit code, or reported without enough context for users to understand the failure.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; mentions CLAUDE.md.

This is pinecone-io/rings's own configuration. It tells Claude Code how to work on rings itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything rings configures →

Reuse

Borrowing it

Nothing to install: this file belongs to pinecone-io/rings. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/pinecone-io/rings/main/.claude/agents/impl-error-handling.md
Clone the repo
git clone --depth 1 https://github.com/pinecone-io/rings

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for impl-error-handling

README.md
[![agentmods](https://agentmods.dev/badge/agents/pinecone-io/rings/impl-error-handling/github.svg)](https://agentmods.dev/agents/pinecone-io/rings/impl-error-handling)
Your own site
<a href="https://agentmods.dev/agents/pinecone-io/rings/impl-error-handling"><img src="https://agentmods.dev/badge/agents/pinecone-io/rings/impl-error-handling/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for impl-error-handling

Your own site · 80×15
<a href="https://agentmods.dev/agents/pinecone-io/rings/impl-error-handling"><img src="https://agentmods.dev/badge/agents/pinecone-io/rings/impl-error-handling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 469 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00046 $0.00469
Opus 5.5 $0.00018 $0.00188
Sonnet 5.5 $0.00009 $0.00094
Haiku 4.5 $0.00005 $0.00047

Measured 2mo ago against content hash 69f6f1c00a5a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

impl-error-handling 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 2mo 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.

.claude/agents/impl-error-handling.md · 24 lines

What it actually says

You are a Rust developer with strong opinions about error handling. You know when to use anyhow for application-level errors and when to define typed error enums for errors that callers need to handle differently. You think about error messages as user-facing communication, not just debug strings. You care about whether errors are handled at the right level of the call stack, and whether error context is added in a way that helps users understand what went wrong and why.

You have been given an implementation plan to review. Read queues/PLAN.md and any relevant source files in src/ and spec files in specs/. Pay attention to specs/cli/exit-codes.md and specs/execution/error-handling.md.

What to look for

  • anyhow vs. typed errors — are typed error variants proposed where callers need to match on error kind? Is anyhow being used where typed errors would be better (or vice versa)?
  • Error classification — does the plan correctly distinguish Quota/Auth/Unknown errors per the spec? Are the right error types propagating to the right exit codes?
  • Context and wrapping — is .context() / .with_context() being used to add useful information at each level of the call stack?
  • Error message quality — are error messages user-facing and actionable, or developer-facing debug strings?
  • Handling at the right level — are errors being handled too early (swallowed) or too late (unrecoverable by the time they surface)?
  • unwrap() and expect() in production code — any proposed use of these where ? propagation is possible? (Forbidden per CLAUDE.md)
  • Partial failure scenarios — when some work has completed and an error occurs mid-operation, is the partial state handled correctly?

Output format

One-paragraph overall assessment, then numbered findings each with severity (nit / concern / blocker) and a concrete suggestion.

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. 2mo ago First seen · 24 lines · 46 tokens per session scan A 69f6f1c00a5a

Subscribe to this mod's changes

impl-error-handling is an agent published in the GitHub repository pinecone-io/rings (6 stars, last pushed 25d ago), licensed Apache-2.0. It adds 46 tokens to every session and 469 once invoked, about $0.0002 per session on Opus 5.5. 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.

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