Agent skill · Microsoft (.NET)

Analyze .NET Performance skill for Claude Code, Codex and Cursor

Scans .NET code for common performance anti-patterns in async, memory, LINQ and I/O.

Officialname: analyzing-dotnet-performance★ 5.7k (repo)pushed 2026-10-24MITSKILL.md on GitHubchecked 2026-11-07

What it does, in the publisher's words

Scans .NET code for ~50 performance anti-patterns across async, memory, strings, collections, LINQ, regex, serialization, and I/O with tiered severity classification. Use when analyzing .NET code for optimization opportunities, reviewing hot paths, or auditing allocation-heavy patterns.

The description field of the SKILL.md. The agent reads only this at startup and decides from it when to load the full skill.

Install Analyze .NET Performance

The skills CLI copies the skill into the folder of each agent you pick (Claude Code, Codex, Cursor, Copilot, Gemini CLI, OpenCode, Windsurf...). Add -g for all projects. Needs Node.js 22.20+. docs

npx skills add dotnet/skills --skill analyzing-dotnet-performance

This repo is a plugin marketplace. Inside Claude Code, add it and install the plugin that holds the skill (dotnet, dotnet-advanced, dotnet-data, dotnet-diag...), or copy only this skill into ~/.claude/skills. docs

/plugin marketplace add dotnet/skills
/plugin install <plugin>@dotnet-agent-skills

# or only this skill:
npx skills add dotnet/skills --skill analyzing-dotnet-performance -a claude-code

Download the skill folder, zip it, then Customize > Skills > + > Create skill > Upload a skill. Code execution must be on (Settings > Capabilities). docs

git clone --depth 1 https://github.com/dotnet/skills.git /tmp/analyzing-dotnet-performance-src
cp -r /tmp/analyzing-dotnet-performance-src/plugins/dotnet-diag/skills/analyzing-dotnet-performance ./analyzing-dotnet-performance
zip -r analyzing-dotnet-performance.zip analyzing-dotnet-performance

Codex reads skills from .agents/skills in the repo or ~/.agents/skills. Type $ in Codex to use one. docs

npx skills add dotnet/skills --skill analyzing-dotnet-performance -a codex

gh skill (GitHub CLI 2.90+, preview) installs it for Copilot in VS Code, the CLI and the cloud agent. Copilot also reads .github/skills and ~/.copilot/skills. docs

gh skill install dotnet/skills analyzing-dotnet-performance

Cursor reads .cursor/skills, .agents/skills and ~/.cursor/skills (and .claude/skills). It does not install loose skills from a GitHub URL, so copy it in. docs

npx skills add dotnet/skills --skill analyzing-dotnet-performance -a cursor

Installs from the GitHub repo; --path picks this skill out of the repo. Default scope is user (all projects). docs

gemini skills install https://github.com/dotnet/skills.git --path plugins/dotnet-diag/skills/analyzing-dotnet-performance

OpenCode reads .opencode/skills, ~/.config/opencode/skills and the Claude and .agents folders. docs

npx skills add dotnet/skills --skill analyzing-dotnet-performance -a opencode

Windsurf (now Devin Desktop) reads .devin/skills, .windsurf/skills and ~/.codeium/windsurf/skills. docs

npx skills add dotnet/skills --skill analyzing-dotnet-performance -a windsurf

Works with

Claude Code, Claude.ai and Claude Desktop, Codex, GitHub Copilot, Cursor, Gemini CLI, OpenCode, Windsurf and other agents that read the open Agent Skills format.

What's in the SKILL.md

13 sections

When to Use
When Not to Use
Inputs
Workflow
Step 1: Load Critical Reference
Step 2: Detect Code Signals and Select Topic Recipes
Step 3: Scan and Report
Step 3b: Cross-File Consistency Check
Step 3c: Compound Allocation Check
Step 4: Classify and Prioritize Findings
Step 5: Generate Findings
Validation
Common Pitfalls

Bundled files

references/async-patterns.md
references/collections-and-linq.md
references/critical-patterns.md
references/io-and-serialization.md
references/memory-and-strings.md
references/regex-patterns.md
references/structural-patterns.md

Loaded only when the instructions point to them.

Facts

Skill name: analyzing-dotnet-performance
Publisher: Microsoft (.NET) (official)
Repo: dotnet/skills
License: MIT
SKILL.md size: 1,478 words, 205 lines
Bundled files: 7, 7 docs
Repo stars: 5.7k (as of 2026-10-24)
SKILL.md checked: 2026-11-07

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FAQ

What does the analyzing-dotnet-performance skill do?+

Scans .NET code for common performance anti-patterns in async, memory, LINQ and I/O. In its own SKILL.md, Microsoft (.NET) describes it as: "Scans .NET code for ~50 performance anti-patterns across async, memory, strings, collections, LINQ, regex, serialization, and I/O with tiered severity classification. Use when analyzing .NET code for optimization opportunities, reviewing hot paths, or auditing allocation-heavy patterns."

How do I install the analyzing-dotnet-performance skill?+

Run npx skills add dotnet/skills --skill analyzing-dotnet-performance and pick your agents, or use the tab for your agent above. In Claude Code the skill ends up in ~/.claude/skills/analyzing-dotnet-performance/SKILL.md; in Codex and Cursor in .agents/skills/analyzing-dotnet-performance/.

Does Analyze .NET Performance work in Codex, Cursor and Copilot, or only Claude?+

It's a standard SKILL.md, so any agent that reads the Agent Skills format can use it: Claude Code, the Claude apps, Codex, GitHub Copilot, Cursor, Gemini CLI, OpenCode, Windsurf and more.

Who maintains Analyze .NET Performance?+

Microsoft (.NET), the company or project behind it, in the dotnet/skills repo on GitHub, last pushed 2026-10-24. License: MIT.

Read a skill's SKILL.md and scripts before you install it: skills aren't verified by any agent vendor. Claude skills marketplace · How to install skills · MCP servers