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.
npx skills add euxx/claude-skills-for-copilot --skill silent-failure-huntergit clone --depth 1 https://github.com/euxx/claude-skills-for-copilotWrote 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/euxx/claude-skills-for-copilot/silent-failure-hunter)<a href="https://agentmods.dev/skills/euxx/claude-skills-for-copilot/silent-failure-hunter"><img src="https://agentmods.dev/badge/skills/euxx/claude-skills-for-copilot/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/skills/euxx/claude-skills-for-copilot/silent-failure-hunter"><img src="https://agentmods.dev/badge/skills/euxx/claude-skills-for-copilot/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 | $0.00044 | $0.00624 |
| Opus 5 | $0.00022 | $0.00312 |
| Sonnet 5 | $0.00009 | $0.00125 |
| Haiku 4.5 | $0.00004 | $0.00062 |
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 11d 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 — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Silent Failure Hunter
Audit error handling code for silent failures, inadequate user feedback, and unjustified fallback behavior. Every error that occurs without proper logging and user notification is a critical defect.
Core Principles (non-negotiable)
- Silent failures are unacceptable — any error without proper logging and user notification is a critical defect.
- Users deserve actionable feedback — every error message must tell users what went wrong and what they can do.
- Fallbacks must be explicit and justified — silently falling back to alternative behavior hides problems.
- Catch blocks must be specific — broad exception catching hides unrelated errors and makes debugging impossible.
- Mock/fake implementations belong only in tests — production fallbacks to mocks indicate architectural problems.
Review Process
1. Identify All Error Handling Code
Systematically locate:
- All try/catch blocks
- All error callbacks and error event handlers
- All conditional branches that handle error states
- All fallback logic and default values used on failure
- Optional chaining (
?.) used in error handlers or callbacks where errors should be explicitly handled (not general null-safe property access)
2. Scrutinize Each Error Handler
For every error handling location:
Logging quality: Is the error logged with appropriate severity and context? Would this log help debug the issue months from now?
User feedback: Does the user receive clear, actionable feedback? Is the error message specific enough to be useful?
Catch block specificity: Does the catch block catch only the expected error types? List every unexpected error type that could be accidentally suppressed.
Fallback behavior: Is the fallback explicitly justified? Does it mask the underlying problem? Would the user be confused by the fallback rather than seeing an error?
Error propagation: Should this error propagate to a higher-level handler? Is it being swallowed when it should bubble up?
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.
- 11d ago First seen · 62 lines · 44 tokens per session scan A fb57691f0340
silent-failure-hunter is a skill published in the GitHub repository euxx/claude-skills-for-copilot (4 stars, last pushed 2mo ago), licensed MIT. It adds 44 tokens to every session and 624 once invoked, about $0.0002 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.
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