mcp-server-ppt: Instructions file for GitHub Copilot

MCP LLM Guidance Creation Guide

How to create effective guidance for LLMs consuming the MCP server

Core Principle

Write FOR expert LLMs (GitHub Copilot, Claude), not ABOUT the system.

LLMs already know PowerPoint, JSON, and MCP protocol. They need server-specific patterns only.

What to Include

1. Action Catalog:

• Complete list of valid action values
• Example: "Actions: get-values, set-values, clear-all"

2. Action Disambiguation:

• When to use each action
• Example: "clear-all removes formatting, clear-contents preserves it"

3. Tool Selection:

• When to use this tool vs other tools
• Example: "Use shape for content, slide for lifecycle"

4. Server-Specific Behavior:

• Quirks of THIS implementation
• Example: "Single cell returns [[value]] (2D array), not scalar"
• Example: "For named ranges, use sheetName='' (empty string)"

5. Common Mistakes:

• Pitfalls specific to this server
• Example: "Don't forget batch mode for multiple operations"

6. Parameter Value Examples:

• Actual values for string parameters
• Example: rangeAddress can be "A1", "A1:C10", or "SalesData"

What to Exclude

❌ DON'T explain:

• PowerPoint concepts (slides, shapes, animations)
• JSON syntax
• Programming basics (arrays, null, types)
• MCP protocol syntax
• Parameter types/requirements (schema provides)

Prompt File Structure

## [Tool Name] Tool

**Actions**: [comma-separated list]

**When to use [tool_name]**:
- [Scenario 1]
- Use [other_tool] for [different scenario]

**Server-specific behavior**:
- [Quirk 1]
- [Quirk 2]

**Action guide**:
- [action-name]: [What makes this different]
- [action-name]: [When to choose this]

**Common mistakes**:
- [Mistake 1 specific to this server]

Length Guidelines

• ✅ One markdown file per tool
• ✅ 50-150 lines total per tool
• ✅ Focus on disambiguation, not explanation
• ❌ Don't write PowerPoint tutorials
• ❌ Don't explain JSON syntax

Format Guidelines

All MCP prompts are auto-generated from skills/shared/*.md:

• Source of truth: skills/shared/*.md — edit these files
• Auto-embedded and auto-generated PptSkillPrompts.g.cs at build time
• NEVER create hand-crafted prompt files — add .md to skills/shared/ instead
• To add a new prompt: add .md to skills/shared/, add description override in GenerateSkillPromptsClass task in McpServer.csproj, rebuild