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 agentmods add skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistantnpx skills add StefanTheCode/dotnet-ai-toolkit --skill hotpath-profiler-assistantgit clone --depth 1 https://github.com/StefanTheCode/dotnet-ai-toolkitWrote 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/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant)<a href="https://agentmods.dev/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant"><img src="https://agentmods.dev/badge/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant.svg" alt="Measured on agentmods" 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 | $0.00123 | $0.00672 |
| Opus 5 | $0.00062 | $0.00336 |
| Sonnet 5 | $0.00025 | $0.00134 |
| Haiku 4.5 | $0.00012 | $0.00067 |
Grade A, and why
hotpath-profiler-assistant 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 4d 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 — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hot-Path Profiler Assistant
Find where time and allocations actually go before optimizing anything — pick the right tool, capture a useful trace, and interpret it. Stops premature optimization of cold code.
Input — point it at your project / describe the symptom
Works on a target (a project or GitHub URL) for context, plus the symptom (slow endpoint, high CPU, latency spikes). If they have a trace already, go to interpretation.
Pick the tool
dotnet-counters— live, low-overhead metrics (CPU, GC, thread pool, requests). Start here to see what kind of problem it is.dotnet-trace— sampling/event trace of CPU time; cross-platform; open in Speedscope/PerfView. Best for "where is CPU spent".dotnet-gcdump/dotnet-dump— heap snapshots for memory leaks/retention.- PerfView (Windows) — deep ETW analysis, allocation tick, GC.
- VS / Rider profiler — IDE-integrated, friendly flame graphs.
Capture (examples)
dotnet-counters monitor -p <pid>
dotnet-trace collect -p <pid> --duration 00:00:30 # then open the .nettrace in speedscope.app
dotnet-gcdump collect -p <pid> # heap snapshot
For an endpoint, drive load while capturing (e.g. bombardier/k6) so the hot path is exercised.
Reading it
- Flame graph width = time — widest frames are where you optimize. Ignore narrow ones.
- Separate CPU-bound (busy frames) from wait (async/IO) — different fixes.
- Check allocations alongside CPU — GC time can masquerade as slowness.
- Confirm the suspected method is actually hot before touching it.
Principles
- Profile first, optimize second. Most "obvious" bottlenecks are wrong guesses.
- Measure under realistic load, not a single cold request.
- Optimize the widest frame, re-measure, repeat — don't shotgun.
How to use it & best prompts
"What's slow in my app", "where's the bottleneck in this endpoint", "how do I capture a CPU trace", "read this flame graph / trace". Feeds into benchmarkdotnet-setup, memory-allocation-analyzer, gc-pressure-auditor.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 4d ago First seen · 43 lines · 123 tokens per session scan A 54d9c181f494
hotpath-profiler-assistant is a skill published in the GitHub repository StefanTheCode/dotnet-ai-toolkit (19 stars, last pushed 25d ago), licensed MIT. It adds 123 tokens to every session and 672 once invoked, about $0.0006 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 2026-08-30.
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