mcp-server-ppt: Instructions file for GitHub Copilot

Exposing Core Commands

Adding a Core method is enough. The CLI command, the MCP tool and the action enum are generated from the interface — do not hand-write them.

How the tool surface is produced

Three attributes on a Core interface drive everything:

Attribute	Where	Produces
[ServiceCategory("section")]	interface	The service registry entry and the CLI command name
[McpTool("section", Title = ..., Description = ...)]	interface	The MCP tool, its title and the description sent to LLMs
[ServiceAction("add")]	method	One action on both entry points, plus the enum member

The generators emit:

• ServiceRegistry.<Tool>.g.cs in PptMcp.Core — the action enum and dispatch
• McpTool.<Tool>.g.cs in PptMcp.McpServer — the MCP tool

Because the CLI and the MCP server are generated from the same interface, they cannot drift apart. There is no ToolActions.cs and no ActionExtensions.cs to keep in sync; both were removed with the hand-maintained architecture.

Adding an operation

// 1. Declare it on the interface, with an action name and XML documentation.
//    The XML docs become the descriptions an LLM sees, so write them for a
//    reader who cannot see the implementation.
[ServiceAction("duplicate")]
OperationResult Duplicate(IPptBatch batch, int slideIndex);

// 2. Implement it in the Commands class. Let exceptions propagate - batch.Execute()
//    converts them into OperationResult { Success = false } (Rule 1b).
public OperationResult Duplicate(IPptBatch batch, int slideIndex) =>
    batch.Execute((ctx, ct) => { /* ... */ });

# 3. Build, so the generators run.
dotnet build

# 4. Write an integration test (Rule 29: the test comes first and must fail
#    before the implementation exists; Rule 30: never a unit test).
dotnet test --filter "Feature=Slide&RunType!=OnDemand"

Then update the counts and the feature reference (Rule 24). FEATURES.md is generated, not hand-edited.