Agent Skills¶
Skills teach your AI assistant how to use Excel MCP Server well. A skill is a small package of guidance and examples that your coding agent (GitHub Copilot, Cursor, Windsurf, Claude Code, and others) loads automatically — so it knows the right workflow, the correct parameters, and the common gotchas without you having to spell them out each time. Installing a skill makes the assistant noticeably more reliable at driving Excel.
There are two packages — pick the one that matches how you connect to Excel (or install both):
| Skill | Component | Distribution | Best For |
|---|---|---|---|
| excel-cli | CLI Tool (excelcli.exe) | Copilot plugin excel-cli, direct skill extraction | Coding agents - token-efficient, --help discoverable |
| excel-mcp | MCP Server (mcp-excel.exe) | Copilot plugin excel-mcp, VS Code extension, MCPB, direct skill extraction | Conversational AI - rich tool schemas |
Shared guidance: skills/shared/*.md — source of truth for both skills (auto-copied to each skill's references/ folder)
Note: Legacy npm packages (
excel-cli-skill,excel-mcp-skill) are no longer published. Use the methods below instead.
Installation¶
GitHub Copilot Plugins (Recommended):
copilot plugin marketplace add sbroenne/mcp-server-excel-plugins
copilot plugin install excel-mcp@mcp-server-excel-plugins
copilot plugin install excel-cli@mcp-server-excel-plugins
Direct skill extraction (for agents without plugin support):
## Via npx (interactive — select excel-cli, excel-mcp, or both)
npx skills add sbroenne/mcp-server-excel
## Or specify directly
npx skills add sbroenne/mcp-server-excel --skill excel-cli
npx skills add sbroenne/mcp-server-excel --skill excel-mcp
Via VS Code Extension (auto-installs excel-mcp): Install the Excel MCP VS Code Extension — it registers the excel-mcp skill via chatSkills. For the excel-cli skill, use the plugin or npx skills methods above.
Maintaining skills and MCP prompts¶
The installed SKILL.md files are generated. Fix their sources rather than editing output that the next build replaces.
| Change | Source |
|---|---|
| Tool or parameter description | Core interface XML documentation and attributes |
| Skill prose and tool-selection rules | templates/SKILL.cli.sbn and templates/SKILL.mcp.sbn |
| Shared workflows, examples, and limitations | shared/*.md |
| Skill rendering behavior | src/ExcelMcp.Build.Tasks/GenerateSkillFile.cs |
| MCP prompt description overrides | GenerateSkillPromptsClass in the MCP Server project file |
Release builds follow two related paths:
Core interfaces -> ServiceRegistryGenerator -> _SkillManifest.g.cs
-> GenerateSkillFile + Scriban templates -> both SKILL.md files
skills/shared/*.md -> copied skill references
-> embedded MCP prompt content + generated ExcelSkillPrompts.g.cs
To add a shared reference, create the Markdown under shared/. Review the MCP prompt description overrides if its automatic description is insufficient. Build the solution in Release, then inspect both skill references and the generated prompt surface for the intended content. The extension packages a copy of the MCP skill; it is not another source.
Write for an agent that already knows Excel and can read tool schemas. Explain which overlapping tool to choose, non-obvious load/save/refresh semantics, destructive effects, and recovery from predictable errors. Add concrete examples when schemas alone cannot explain a workflow, not to duplicate enum catalogs or CLI help.
If a tool is misunderstood in an evaluation, fix the relevant source above, rebuild, and rerun the affected scenario. See the evaluation authoring guide.