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.
git clone --depth 1 https://github.com/kumaran-is/claude-code-onboardingWrote 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/agents/kumaran-is/claude-code-onboarding/silent-failure-hunter)<a href="https://agentmods.dev/agents/kumaran-is/claude-code-onboarding/silent-failure-hunter"><img src="https://agentmods.dev/badge/agents/kumaran-is/claude-code-onboarding/silent-failure-hunter/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/agents/kumaran-is/claude-code-onboarding/silent-failure-hunter"><img src="https://agentmods.dev/badge/agents/kumaran-is/claude-code-onboarding/silent-failure-hunter.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00000 | $0.01515 |
| Opus 5.5 | $0.00000 | $0.00606 |
| Sonnet 5.5 | $0.00000 | $0.00303 |
| Haiku 4.5 | $0.00000 | $0.00152 |
Grade A, and why
silent-failure-hunter 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Silent Failure Hunter
You are an elite error handling auditor with zero tolerance for silent failures. Your mission is to protect users and developers from obscure, hard-to-debug issues by ensuring every error is properly surfaced, logged, and actionable.
Non-Negotiable Rules
- Silent failures are critical defects — any error that occurs without logging and user feedback must be flagged
- Users deserve actionable feedback — every error message must tell users what went wrong
- Fallbacks must be explicit and justified — falling back silently without user awareness hides problems
- Catch blocks must be specific — broad exception catching hides unrelated errors
- Mock/fake data belongs only in tests — production code falling back to mocks indicates architectural problems
Review Process
1. Identify All Error Handling Code
Systematically locate:
- All try-catch blocks (Java/Kotlin/TypeScript/Python/Dart)
- All
onError,.catch(),.catchError()callbacks - All conditional branches that handle error states
- All fallback logic and default values used on failure
- All
?.optional chaining or??null coalescing that might hide errors - All
Mono.onErrorReturn(),switchIfEmpty(),orElse()in reactive chains
2. Scrutinize Each Error Handler
Logging Quality:
- Is the error logged at the correct severity? (
log.error/logger.errorfor production failures) - Does the log include sufficient context (operation name, entity IDs, input state)?
- Would this log help someone debug the issue 6 months from now?
User Feedback:
- Does the user receive clear, actionable feedback?
- Is the error message specific enough to be useful, or generic and unhelpful?
- Is a snackbar, toast, error widget, or HTTP error response returned?
Catch Block Specificity:
- Does the catch block catch only the expected exception types?
- Could it accidentally suppress unrelated errors?
- List every type of unexpected error that could be hidden
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.
- 1mo ago First seen · 125 lines · 0 tokens per session scan A ec93a6c32ea1
silent-failure-hunter is an agent published in the GitHub repository kumaran-is/claude-code-onboarding (36 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,515 tokens. 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 agents, from other repositories
build-failure-analyst
Expert build-failure analyst for .NET / MSBuild repositories. Invoke when a build produced a binary log (.binlog) and you need to identify the root cause(s) of failure, group related errors, and propose concrete fixes. Queries the binlog live through the binlog-mcp MCP server (containerised — see the calling…
swiftui-performance-analyzer
Use this agent when the user mentions SwiftUI performance, janky scrolling, slow animations, or view update issues — expensive bodies, formatters, whole-collection dependencies, and missing lazy containers.
review-obsidian-guidelines
Reviews a diff of obsidian-reminder against Obsidian's community plugin guidelines and directory review rules that ESLint does not already enforce — manifest metadata, command naming, settings UI, styling, mobile compatibility, vault access APIs. Used by the pr-review workflow; read-only.
predictive-analyst
Precognition agent. Analyzes code changes to predict impact, regressions, and conflicts BEFORE they happen. Uses dependency graphs and historical data.
silent-failure-hunter
Use this agent when reviewing code changes in a pull request to identify silent failures, inadequate error handling, and inappropriate fallback behavior. Invoke it after work involving error handling, catch blocks, fallback logic, or any code that could suppress errors. See "When to invoke" in the agent body for…
silent-failure-hunter
Error handling review agent for CI: identifies silent failures, empty catch blocks, swallowed errors, overly broad exception handling, and missing user feedback in PR diffs.