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 Jamie-BitFlight/claude_skills --skill test-failure-mindsetgit clone --depth 1 https://github.com/Jamie-BitFlight/claude_skillsWrote 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/jamie-bitflight/claude_skills/test-failure-mindset)<a href="https://agentmods.dev/skills/jamie-bitflight/claude_skills/test-failure-mindset"><img src="https://agentmods.dev/badge/skills/jamie-bitflight/claude_skills/test-failure-mindset/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/jamie-bitflight/claude_skills/test-failure-mindset"><img src="https://agentmods.dev/badge/skills/jamie-bitflight/claude_skills/test-failure-mindset.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 | $0.00074 | $0.00538 |
| Opus 5 | $0.00037 | $0.00269 |
| Sonnet 5 | $0.00015 | $0.00108 |
| Haiku 4.5 | $0.00007 | $0.00054 |
Grade A, and why
test-failure-mindset 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 3d 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 — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test Failure Analysis Mindset
Establish a balanced investigative approach for all test failures encountered in this session.
Core Principle
Tests are specifications - they define expected behavior.
Dual Hypothesis Approach
Always consider both possibilities when a test fails:
| Hypothesis A | Hypothesis B |
|---|---|
| Test expectations are incorrect | Implementation has a bug |
| Test is outdated | Test caught a regression |
| Test has wrong assumptions | Test found an edge case |
Investigation Protocol
For EVERY test failure:
1. Pause and Read
- Understand what the test is trying to verify
- Read its name, comments, and assertions
- Check the test's history (git blame) for context
2. Trace the Implementation
- Follow the code path that leads to the failure
- Understand actual behavior vs. expected behavior
- Check if recent changes affected this code path
3. Consider the Context
- Is this testing a documented requirement?
- Would current behavior surprise a user?
- What would be the impact of each possible fix?
4. Make a Reasoned Decision
| Situation | Action |
|---|---|
| Implementation is wrong | Fix the bug |
| Test is wrong | Fix test AND document why |
| Unclear | Seek clarification before changing |
5. Learn from the Failure
- What can this teach about the system?
- Should additional tests cover related cases?
- Is there a pattern being missed?
Red Flags (Dangerous Patterns)
- Immediately changing tests to match implementation
- Assuming implementation is always correct
- Bulk-updating tests without individual analysis
- Removing "inconvenient" test cases
- Adding mock/stub workarounds instead of fixing root causes
Good Practices
- Treat each test failure as a potential bug discovery
- Document analysis in comments when fixing tests
- Write clear test names that explain intent
- Consider adding more tests when finding ambiguity
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.
- 3d ago First seen · 80 lines · 74 tokens per session scan A 9b207dd122ce
test-failure-mindset is a skill published in the GitHub repository Jamie-BitFlight/claude_skills (66 stars, last pushed today), licensed MIT. It adds 74 tokens to every session and 538 once invoked, about $0.0004 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 2026-09-06.
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