Borrowing it
Nothing to install: this file belongs to adrian-d-hidalgo/nestjs-mcp-server. 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/adrian-d-hidalgo/nestjs-mcp-server/main/.claude/skills/bug-diagnosis/SKILL.mdgit clone --depth 1 https://github.com/adrian-d-hidalgo/nestjs-mcp-serverWrote 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/adrian-d-hidalgo/nestjs-mcp-server/bug-diagnosis)<a href="https://agentmods.dev/skills/adrian-d-hidalgo/nestjs-mcp-server/bug-diagnosis"><img src="https://agentmods.dev/badge/skills/adrian-d-hidalgo/nestjs-mcp-server/bug-diagnosis/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/adrian-d-hidalgo/nestjs-mcp-server/bug-diagnosis"><img src="https://agentmods.dev/badge/skills/adrian-d-hidalgo/nestjs-mcp-server/bug-diagnosis.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 | $0.00069 | $0.05936 |
| Opus 5.5 | $0.00028 | $0.02374 |
| Sonnet 5.5 | $0.00014 | $0.01187 |
| Haiku 4.5 | $0.00007 | $0.00594 |
Grade A, and why
bug-diagnosis 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.
How it starts
The opening of the file, as written. The whole thing — 432 lines — stays where its author put it; the contents beside it link to each section on GitHub.
The library difference: there is no running production system to read logs from. Every piece
of evidence here has to be created — a failing spec, an e2e run, an Inspector session, a running
example. That makes Phase 2 more work than in an application, and makes the temptation to skip
straight to a plausible-sounding cause much stronger. Resist it: CLAUDE.md is explicit that
"a fix grounded in [Inference] is not done — get the evidence or say you couldn't and stop."
Read it and its comments (issue_read) as the verbatim report, then run Phase 0 → 4 here.
The failure output IS Phase 0's capture and often most of Phase 2's evidence. Start at Phase 1 — the deprecation check still applies.
Run Phase 0 → 4 here directly.
Use the github-issues skill (Mode B) to shape and propose it.
Report why — a deprecated path, a consumer misuse, an upstream SDK bug. Each has a different outcome and none of them is silence.
If unsure where to start: start at Phase 0.
| Field | For this project |
|---|---|
| Exact wording | the error string, the tsc diagnostic (TS2589), the SDK error, the issue title — verbatim |
| Where | which export or decorator (@Tool, @Resource, @Prompt), which protocol era (2026-07-28 modern vs the 2025 legacy fallback), which module option |
| Versions | @nestjs-mcp/server, @nestjs/common, @modelcontextprotocol/sdk, TypeScript, Node |
| When | which version it started at, or whether it ever worked |
| Expected vs observed | what the consumer expected, and what actually happened |
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 · 432 lines · 69 tokens per session scan A 0c026188915e
bug-diagnosis is a skill published in the GitHub repository adrian-d-hidalgo/nestjs-mcp-server (40 stars, last pushed 29d ago), licensed MIT. It adds 69 tokens to every session and 5,936 once invoked, about $0.0003 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.
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