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 alexei-led/cc-thingz --skill writing-csharpgit clone --depth 1 https://github.com/alexei-led/cc-thingzWrote 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/alexei-led/cc-thingz/writing-csharp)<a href="https://agentmods.dev/skills/alexei-led/cc-thingz/writing-csharp"><img src="https://agentmods.dev/badge/skills/alexei-led/cc-thingz/writing-csharp.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 5.1 | $0.00099 | $0.00769 |
| Opus 5 | $0.00049 | $0.00385 |
| Sonnet 5 | $0.00020 | $0.00154 |
| Haiku 4.5 | $0.00010 | $0.00077 |
Grade A, and why
writing-csharp 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 7d 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 — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C# /.NET Development
Use only for C# and .NET code. Follow the project's SDK, target frameworks, nullable settings, analyzer config, test stack, and local conventions.
Read First
Read principles.md before writing, changing, or reviewing C# code. Read conditional references only when the change touches that area.
Conditional References
- patterns.md — solution layout, ASP.NET Core boundaries, DI, EF access, config, and worker patterns.
- testing.md — adding or reshaping xUnit, NUnit, or MSTest coverage; keep the local
dotnet testloop fast. - linting.md — changing
dotnet format, analyzers, warning policy, or slow verification flow. - cli.md — writing or changing .NET CLIs.
Project Baseline
- Inspect the nearest
*.csproj,Directory.Build.props,global.json, solution file, CI, and nearby code before using SDK- or framework-specific APIs. - Keep nullable reference types enabled. Fix the warning or model, not the warning level.
- Prefer the BCL and existing NuGet packages before adding a dependency.
- Use the existing app style: ASP.NET Core controllers vs minimal APIs, records vs classes, MediatR or no mediator, EF or raw SQL, and the configured test framework.
Comments and XML Docs
- Use XML documentation comments for public APIs when the project emits API docs or enforces CS1591.
- Summarize contracts, invariants, edge cases, and effects. Do not restate member names or signatures.
- Use
//for brief implementation notes; avoid long/* */explanations. - Keep comments short. Move longer rationale to docs, issue links, or design notes.
- Do not comment obvious code.
- Keep tests readable without comments; add one only for unobvious fixtures, timing, concurrency, external services, or regression context.
Verification
Run focused dotnet checks while editing, then the project-configured build,
tests, analyzers, and formatting checks before final output. Prefer the
narrowest useful project or solution target for the hot loop, then the broader
configured command before final output.
What ships with it
6 files 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.
- 7d ago First seen · 67 lines · 99 tokens per session scan A 2aea31005a07
writing-csharp is a skill published in the GitHub repository alexei-led/cc-thingz (35 stars, last pushed 1mo ago), licensed MIT. It adds 99 tokens to every session and 769 once invoked, about $0.0005 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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