Executor is a shared integration layer that lets AI agents use tools from MCP servers, OpenAPI specifications, GraphQL APIs, and custom JavaScript functions through one catalog. It centralizes credentials and per-tool access policies so MCP-compatible agents can reuse the same integrations.
Borrowing it
Nothing to install: this file belongs to UsefulSoftwareCo/executor. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/UsefulSoftwareCo/executor/main/.agents/skills/wrdn-effect-typed-errors/SKILL.mdgit clone --depth 1 https://github.com/UsefulSoftwareCo/executorWrote 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.
[](https://agentmods.dev/skills/usefulsoftwareco/executor/wrdn-effect-typed-errors)<a href="https://agentmods.dev/skills/usefulsoftwareco/executor/wrdn-effect-typed-errors"><img src="https://agentmods.dev/badge/skills/usefulsoftwareco/executor/wrdn-effect-typed-errors/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.
<a href="https://agentmods.dev/skills/usefulsoftwareco/executor/wrdn-effect-typed-errors"><img src="https://agentmods.dev/badge/skills/usefulsoftwareco/executor/wrdn-effect-typed-errors.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00062 | $0.02716 |
| Opus 5.5 | $0.00025 | $0.01086 |
| Sonnet 5.5 | $0.00012 | $0.00543 |
| Haiku 4.5 | $0.00006 | $0.00272 |
Grade A, and why
wrdn-effect-typed-errors 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- wrdn-effect-typed-errors — 100% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 360 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You fix one family of patterns: untyped JavaScript error handling in Effect code.
The preferred boundary is typed Schema.TaggedError / Data.TaggedError values in the Effect error channel. Construct the tagged error directly at the failure site unless a helper performs real classification or normalization.
Trace before changing
- Identify the boundary. Is this Effect domain code, React UI code, a third-party callback, or plain test/tooling code?
- Find the existing domain errors. Check nearby
errors.ts,Schema.TaggedError,Data.TaggedError, and API.addError(...)declarations before adding a new class. - Decide whether a new error is needed. Add a new tagged error only if callers have a distinct recovery path, HTTP status, UI affordance, retry policy, or telemetry classification.
- Preserve failure semantics. If the old code failed, the new code should fail in the Effect error channel. Do not replace thrown failures with fallback values like
false,null,undefined,[], or"unknown"unless the existing contract already treats that condition as non-fatal. - Preserve the typed channel. Do not convert typed failures into
Error, thrown exceptions,String(error), or.messagereads from unknown values. - Recognize real boundaries. Runtime workers, Vite/CLI tooling, callback APIs, and third-party interfaces may have to throw, catch, or reject at the boundary. Do not contort those files into fake Effect shapes. Keep the boundary idiom when it is contained and immediately wrapped into an Effect error channel, stable IPC envelope, or test/tooling result.
- Do not hide construction behind trivial helpers. Inline
new DomainError(...)unless the helper branches on input or maps an external error format into a domain error.
Preserve behavior first
The lint rule is about where the failure lives, not whether the operation should still fail.
Bad fix: this removes the lint finding by silently changing invalid input into a non-match.
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.
- 2mo ago First seen · 360 lines · 62 tokens per session scan A 16631077797c
wrdn-effect-typed-errors is a skill published in the GitHub repository UsefulSoftwareCo/executor (4,297 stars, last pushed today), licensed MIT. It adds 62 tokens to every session and 2,716 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 2026-08-30.
Other skills, from other repositories
debug-optimize-lcp
Guides debugging and optimizing Largest Contentful Paint (LCP) using Chrome DevTools MCP tools. Use this skill whenever the user asks about LCP performance, slow page loads, Core Web Vitals optimization, or wants to understand why their page's main content takes too long to appear. Also use when the user mentions…
systematic-debugging
Use when debugging a failing test, build error, or runtime issue that isn't immediately obvious. Guides a 4-phase root cause analysis instead of random fix attempts.
log-error-digest
Analyze log files to troubleshoot errors, identify peak error periods, and produce error clustering, frequency statistics, and time distribution reports. Supports JSON, syslog, and Nginx formats with automatic detection. Use when a user uploads a .log file and asks to analyze errors, find patterns, debug issues, or…
cwv-optimizer
Diagnose and fix Core Web Vitals issues on AEM Edge Delivery Services pages. Goes deeper than generic CWV advice by understanding EDS-specific performance patterns including the 100KB LCP budget, E-L-D loading phases, block rendering behavior, and third-party script impact. Produces specific fixes for LCP, CLS, and…
incident-response-incident-response
Coordinate production incident triage, mitigation, investigation, recovery, and follow-up. Use when responding to outages or other incidents that require structured operational coordination.
ci-fixer
CI failures - read error, minimal fix, verify.