roslyn-mcp-dev-conventions

roslyn-mcp-dev-conventions is a cursor rule for Cursor from VuDZ/RoslynMcpServer. It costs 0 tokens per session (251 once invoked), scanned A, original, MIT.

A set of contribution rules for adding tools and services to a C# MCP server. MCP is a protocol that lets an AI assistant call software tools.

In plain words
What is it for?
Use it when changing tool registration, dependency injection, file-path handling, returned messages, logging, unit tests, or version files in this repository.
Why use it?
It prevents new tools from being registered in the wrong place, using unsafe file paths, leaking internal errors, or skipping the expected tests and documentation updates.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/. Also seen: mentions AGENTS.md.

Good fit Use it when changing tool registration, dependency injection, file-path handling, returned messages, logging, unit tests, or version files in this repository.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions
Install

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.

Clone the repo
git clone --depth 1 https://github.com/VuDZ/RoslynMcpServer

Made for: Cursor.

Wrote 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.

agentmods badge for roslyn-mcp-dev-conventions

README.md
[![agentmods](https://agentmods.dev/badge/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions/github.svg)](https://agentmods.dev/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions)
Your own site
<a href="https://agentmods.dev/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions"><img src="https://agentmods.dev/badge/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions/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.

agentmods 80×15 button for roslyn-mcp-dev-conventions

Your own site · 80×15
<a href="https://agentmods.dev/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions"><img src="https://agentmods.dev/badge/rules/vudz/roslynmcpserver/roslyn-mcp-dev-conventions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 251 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00251
Opus 5 $0.00000 $0.00125
Sonnet 5 $0.00000 $0.00050
Haiku 4.5 $0.00000 $0.00025

Measured 2d ago against content hash a5802a1a5d53, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-16, from the pricing page.

Security

Grade A, and why

roslyn-mcp-dev-conventions 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 2d 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.

.cursor/rules/roslyn-mcp-dev-conventions.mdc · 17 lines

What it actually says

Tools & Services changes

  • Register new tools in McpToolCatalog (names, host, group, lite-core, read/write). That catalog drives DI host registration and method-level MCP SDK registration. Do not add a parallel WithTools<T>() list.
  • Constructor-inject SolutionManager / helpers; tools are singletons.
  • Resolve all relative file paths via ResolvePathAgainstWorkspace.
  • Prefer structured return strings (markdown sections, ### metadata) matching existing tools.
  • Log outcomes as summary + warning highlights; gate full dumps behind ROSLYN_MCP_LOG_TOOL_OUTPUT=full.
  • Friendly errors for bad/missing args — avoid unhandled exceptions leaking as opaque MCP failures.
  • Add/adjust unit tests under RoslynMcpServer.Tests for parsers, resolvers, path helpers.
  • Version: follow always-apply rule roslyn-mcp-version-bump.mdc — patch-bump after successful self-build when shipping code/tool changes; sync README + AGENTS.md.sample.
Changes

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.

  1. 2d ago First seen · 17 lines · 0 tokens per session scan A a5802a1a5d53

Subscribe to this mod's changes

roslyn-mcp-dev-conventions is a cursor rule published in the GitHub repository VuDZ/RoslynMcpServer (7 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 251 tokens. 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 2026-09-14.