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/modelcontextprotocol/csharp-sdk/prepare-releasenpx skills add modelcontextprotocol/csharp-sdk --skill prepare-releasegit clone --depth 1 https://github.com/modelcontextprotocol/csharp-sdkWhat 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 | $0.00088 | $0.07404 |
| Opus 5 | $0.00044 | $0.03702 |
| Sonnet 5 | $0.00018 | $0.01481 |
| Haiku 4.5 | $0.00009 | $0.00740 |
Grade A, and why
prepare-release 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 yesterday.
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.
The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
What ships with it
4 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.
- yesterday First seen · 453 lines · 88 tokens per session scan A 6cf3a56acdfb
prepare-release is a skill published in the GitHub repository modelcontextprotocol/csharp-sdk (4,500 stars, last pushed 4d ago), with no licence file. It adds 88 tokens to every session and 7,404 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 2026-08-30.
Other skills, from other repositories
develop-ownplanner-feature
Plan, review, implement, and verify an OwnPlanner feature or use case from a GitHub issue, issue URL, repository plan, or direct feature request. Use for new product behavior and cross-layer enhancements that may affect Domain, Application, Infrastructure, Web API, MCP, console/stdio, React frontend, tests…
widget-creator
Step-by-step guide for creating new widgets in the Hex1b TUI library. Use when implementing new widgets from scratch, including widget records, nodes, extension methods, theming, reconciliation, and tests.
aspire
Orchestrates Aspire distributed applications using the Aspire CLI for running, debugging, and managing distributed apps. USE FOR: aspire start, aspire stop, start aspire app, aspire describe, list aspire integrations, debug aspire issues, view aspire logs, add aspire resource, aspire dashboard, update aspire apphost.…
nina-repository
Repository-specific guidance for working in the N.I.N.A. codebase and NINA.sln. Use when Codex is asked to modify, review, test, debug, navigate, or explain code in this repository; touch NINA. projects, app startup/DI, profiles/settings, localization, database migrations, equipment, astrometry, imaging, plate…
csharp-dotnet
Use when writing, reviewing, testing, or shipping C# / .NET code — ASP.NET Core APIs (minimal APIs vs controllers), EF Core data access, async correctness, solution layout in .cs/.csproj/.sln. NOT a Java/Spring backend (that is spring-boot), NOT a Node/TypeScript backend (that is nestjs), NOT framework-neutral REST…
geometry-api-net
Use when working with Esri geometry types (Point, Polyline, Polygon, Envelope) in .NET/C# — spatial operations, JSON/GeoJSON/WKT I/O, geodesic calculations. Esri Geometry API for .NET.