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 Attemainio/dotnet-toolkit --skill dotnet-performancegit clone --depth 1 https://github.com/Attemainio/dotnet-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/attemainio/dotnet-toolkit/dotnet-performance)<a href="https://agentmods.dev/skills/attemainio/dotnet-toolkit/dotnet-performance"><img src="https://agentmods.dev/badge/skills/attemainio/dotnet-toolkit/dotnet-performance/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/attemainio/dotnet-toolkit/dotnet-performance"><img src="https://agentmods.dev/badge/skills/attemainio/dotnet-toolkit/dotnet-performance.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 | $0.00376 | $0.11902 |
| Opus 5.5 | $0.00150 | $0.04761 |
| Sonnet 5.5 | $0.00075 | $0.02380 |
| Haiku 4.5 | $0.00038 | $0.01190 |
Grade A, and why
dotnet-performance 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 — 646 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Measuring what this plugin costs against not having it
Host requirement
This benchmark depends on the three probe agents' different tool grants, not only their prompts.
Claude Code installs those agent definitions with the plugin. Codex plugins do not currently install
custom-agent registrations, so in Codex run this skill only when the matching agents have already been
made available through Codex's Claude import flow. If they are absent, stop and report that the
benchmark cannot preserve its isolation; substituting unrestricted built-in agents would make the
comparison invalid. The canonical briefs remain under agents/ and must be referenced, not copied.
dotnet-selfeval asks whether the tools are efficient against each other — which route inside the
plugin is cheapest. This skill asks the prior question: is the plugin cheaper than not using it, in
this repo, on this kind of task — and does a real, unrestricted session actually behave the way an
idealized best-case or worst-case comparison assumes? Those are three different questions, and they
can disagree. A tool can be the best route inside the plugin and still lose to grep on a repo of forty
files; a guard that only advises can still go unheeded even when it is right.
The claim under test is the one in the always-loaded rule: that text search gives wrong answers on C#, not merely slower ones, and that the MCP tools cost fewer tokens than the file reads they replace. The first half is a correctness claim and the second is a cost claim. Measure them separately — a route that is cheaper and wrong is not a win, and reporting a single blended number hides exactly that case. A third claim, added when this skill grew a third probe, is a practice claim: does a real session, free to use either tool family and free to ignore an advisory nudge, actually land closer to the ceiling or closer to the floor? A benchmark that only ever plays the two extremes cannot answer that on its own.
Why three subagents, not the orchestrator playing all the routes
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.
- 1mo ago Changed · +47 lines e3d392366018
- 1mo ago Changed · +9 lines 1f45ab5e77b3
- 2mo ago First seen · 590 lines · 376 tokens per session scan A 1fe7bdb3da20
dotnet-performance is a skill published in the GitHub repository Attemainio/dotnet-toolkit (2 stars, last pushed 1mo ago), licensed MIT. It adds 376 tokens to every session and 11,902 once invoked, about $0.0015 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 2026-08-31.
dotnet-performance compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| dotnet-performanceAttemainio/dotnet-toolkit | Skill | 2 | 1mo ago | MIT | A | 376 | Claude Code |
| veladbhq-uk/vela-skill | Skill | 6 | 11d ago | MIT | A | 213 | Claude Code |
| bootstrap-solutiongaelic-ghost/socket | Skill | 9 | 2mo ago | Apache-2.0 | A | 38 | Claude Code |
| build-csharp-projectgaelic-ghost/socket | Skill | 9 | 2mo ago | Apache-2.0 | A | 37 | Claude Code |
| rider-searchJSungMin/rider-mcp-enforcer | Skill | 3 | 23d ago | MIT | A | 60 | Claude Code |
| grasshopper-componentbcshih/rhino-dev-skills | Skill | 1 | 4mo ago | MIT | A | 128 | Claude Code |
| rhinocommon-geometrybcshih/rhino-dev-skills | Skill | 1 | 4mo ago | MIT | A | 151 | Claude Code |