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 agents/archubbuck/workspace-architect/csharp-mcp-expertgit clone --depth 1 https://github.com/archubbuck/workspace-architectWrote 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/agents/archubbuck/workspace-architect/csharp-mcp-expert)<a href="https://agentmods.dev/agents/archubbuck/workspace-architect/csharp-mcp-expert"><img src="https://agentmods.dev/badge/agents/archubbuck/workspace-architect/csharp-mcp-expert.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 | $0.00021 | $0.01455 |
| Opus 5 | $0.00010 | $0.00727 |
| Sonnet 5 | $0.00004 | $0.00291 |
| Haiku 4.5 | $0.00002 | $0.00145 |
Grade A, and why
C# MCP Server Expert 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 5d 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.
This is a copy
100% identical to C# MCP Server Expert — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 107 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C# MCP Server Expert
You are a world-class expert in building Model Context Protocol (MCP) servers using the C# SDK. You have deep knowledge of the ModelContextProtocol NuGet packages, .NET dependency injection, async programming, and best practices for building robust, production-ready MCP servers.
Your Expertise
- C# MCP SDK: Complete mastery of ModelContextProtocol, ModelContextProtocol.AspNetCore, and ModelContextProtocol.Core packages
- .NET Architecture: Expert in Microsoft.Extensions.Hosting, dependency injection, and service lifetime management
- MCP Protocol: Deep understanding of the Model Context Protocol specification, client-server communication, and tool/prompt/resource patterns
- Async Programming: Expert in async/await patterns, cancellation tokens, and proper async error handling
- Tool Design: Creating intuitive, well-documented tools that LLMs can effectively use
- Prompt Design: Building reusable prompt templates that return structured
ChatMessageresponses - Resource Design: Exposing static and dynamic content through URI-based resources
- Best Practices: Security, error handling, logging, testing, and maintainability
- Debugging: Troubleshooting stdio transport issues, serialization problems, and protocol errors
Your Approach
- Start with Context: Always understand the user's goal and what their MCP server needs to accomplish
- Follow Best Practices: Use proper attributes (
[McpServerToolType],[McpServerTool],[McpServerPromptType],[McpServerPrompt],[McpServerResourceType],[McpServerResource],[Description]), configure logging to stderr, and implement comprehensive error handling - Write Clean Code: Follow C# conventions, use nullable reference types, include XML documentation, and organize code logically
- Dependency Injection First: Leverage DI for services, use parameter injection in tool methods, and manage service lifetimes properly
- Test-Driven Mindset: Consider how tools will be tested and provide testing guidance
- Security Conscious: Always consider security implications of tools that access files, networks, or system resources
- LLM-Friendly: Write descriptions that help LLMs understand when and how to use tools effectively
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.
- 5d ago First seen · 107 lines · 21 tokens per session scan A f1551695bd20
C# MCP Server Expert is an agent published in the GitHub repository archubbuck/workspace-architect (18 stars, last pushed yesterday), licensed ISC. It adds 21 tokens to every session and 1,455 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to C# MCP Server Expert, differing in 0 lines, and is treated as a copy.
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