refactor(server): remove legacy InstructionsFunc / WithServerInstructions machinery

Skills are the only guidance surface going forward; the per-toolset
inline instruction system is no longer needed. This removes ~308 lines
of toolset instruction generation.

- Delete pkg/github/toolset_instructions.go (5 generate*ToolsetInstructions
  helpers), pkg/inventory/instructions.go (generateInstructions aggregator),
  and pkg/inventory/instructions_test.go (~265 lines of tests).
- Remove the InstructionsFunc field from inventory.ToolsetMetadata, and
  drop it from the 5 toolsets that used it (Context, Issues, PullRequests,
  Discussions, Projects).
- Remove the generateInstructions field, WithServerInstructions() method,
  and the conditional in Builder.Build() that called generateInstructions(r).
- Remove the instructions field and Instructions() method from Inventory.
- Drop the .WithServerInstructions() call from NewStdioMCPServer
  (internal/ghmcp/server.go) and from DefaultInventoryFactory (pkg/http/handler.go).
- Drop `Instructions: inv.Instructions(),` from the serverOpts assembled
  in NewMCPServer (pkg/github/server.go).

Inspired by the cleanup in github#2374.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: olaservo

internal/ghmcp/server.go

@@ -143,7 +143,6 @@ func NewStdioMCPServer(ctx context.Context, cfg github.MCPServerConfig) (*mcp.Se
 		WithToolsets(github.ResolvedEnabledToolsets(cfg.DynamicToolsets, cfg.EnabledToolsets, cfg.EnabledTools)).
 		WithTools(github.CleanTools(cfg.EnabledTools)).
 		WithExcludeTools(cfg.ExcludeTools).
-		WithServerInstructions().
 		WithFeatureChecker(featureChecker)
 
 	// Apply token scope filtering if scopes are known (for PAT filtering)

pkg/github/server.go

@@ -81,7 +81,6 @@ type MCPServerOption func(*mcp.ServerOptions)
 func NewMCPServer(ctx context.Context, cfg *MCPServerConfig, deps ToolDependencies, inv *inventory.Inventory, middleware ...mcp.Middleware) (*mcp.Server, error) {
 	// Create the MCP server
 	serverOpts := &mcp.ServerOptions{
-		Instructions:      inv.Instructions(),
 		Logger:            cfg.Logger,
 		CompletionHandler: CompletionsHandler(deps.GetClient),
 	}

pkg/github/tools.go

@@ -29,11 +29,10 @@ var (
 		Icon:        "check-circle",
 	}
 	ToolsetMetadataContext = inventory.ToolsetMetadata{
-		ID:               "context",
-		Description:      "Tools that provide context about the current user and GitHub context you are operating in",
-		Default:          true,
-		Icon:             "person",
-		InstructionsFunc: generateContextToolsetInstructions,
+		ID:          "context",
+		Description: "Tools that provide context about the current user and GitHub context you are operating in",
+		Default:     true,
+		Icon:        "person",
 	}
 	ToolsetMetadataRepos = inventory.ToolsetMetadata{
 		ID:          "repos",
@@ -47,18 +46,16 @@ var (
 		Icon:        "git-branch",
 	}
 	ToolsetMetadataIssues = inventory.ToolsetMetadata{
-		ID:               "issues",
-		Description:      "GitHub Issues related tools",
-		Default:          true,
-		Icon:             "issue-opened",
-		InstructionsFunc: generateIssuesToolsetInstructions,
+		ID:          "issues",
+		Description: "GitHub Issues related tools",
+		Default:     true,
+		Icon:        "issue-opened",
 	}
 	ToolsetMetadataPullRequests = inventory.ToolsetMetadata{
-		ID:               "pull_requests",
-		Description:      "GitHub Pull Request related tools",
-		Default:          true,
-		Icon:             "git-pull-request",
-		InstructionsFunc: generatePullRequestsToolsetInstructions,
+		ID:          "pull_requests",
+		Description: "GitHub Pull Request related tools",
+		Default:     true,
+		Icon:        "git-pull-request",
 	}
 	ToolsetMetadataUsers = inventory.ToolsetMetadata{
 		ID:          "users",
@@ -97,10 +94,9 @@ var (
 		Icon:        "bell",
 	}
 	ToolsetMetadataDiscussions = inventory.ToolsetMetadata{
-		ID:               "discussions",
-		Description:      "GitHub Discussions related tools",
-		Icon:             "comment-discussion",
-		InstructionsFunc: generateDiscussionsToolsetInstructions,
+		ID:          "discussions",
+		Description: "GitHub Discussions related tools",
+		Icon:        "comment-discussion",
 	}
 	ToolsetMetadataGists = inventory.ToolsetMetadata{
 		ID:          "gists",
@@ -113,10 +109,9 @@ var (
 		Icon:        "shield",
 	}
 	ToolsetMetadataProjects = inventory.ToolsetMetadata{
-		ID:               "projects",
-		Description:      "GitHub Projects related tools",
-		Icon:             "project",
-		InstructionsFunc: generateProjectsToolsetInstructions,
+		ID:          "projects",
+		Description: "GitHub Projects related tools",
+		Icon:        "project",
 	}
 	ToolsetMetadataStargazers = inventory.ToolsetMetadata{
 		ID:          "stargazers",

pkg/github/toolset_instructions.go

@@ -284,8 +284,6 @@ func DefaultInventoryFactory(cfg *ServerConfig, t translations.TranslationHelper
 		b = InventoryFiltersForRequest(r, b)
 		b = PATScopeFilter(b, r, scopeFetcher)
 
-		b.WithServerInstructions()
-
 		return b.Build()
 	}
 }

pkg/http/handler.go

@@ -50,9 +50,8 @@ type Builder struct {
 	toolsetIDs           []string // raw input, processed at Build()
 	toolsetIDsIsNil      bool     // tracks if nil was passed (nil = defaults)
 	additionalTools      []string // raw input, processed at Build()
-	featureChecker       FeatureFlagChecker
-	filters              []ToolFilter // filters to apply to all tools
-	generateInstructions bool
+	featureChecker FeatureFlagChecker
+	filters        []ToolFilter // filters to apply to all tools
 }
 
 // NewBuilder creates a new Builder.
@@ -95,11 +94,6 @@ func (b *Builder) WithReadOnly(readOnly bool) *Builder {
 	return b
 }
 
-func (b *Builder) WithServerInstructions() *Builder {
-	b.generateInstructions = true
-	return b
-}
-
 // WithToolsets specifies which toolsets should be enabled.
 // Special keywords:
 //   - "all": enables all toolsets
@@ -267,10 +261,6 @@ func (b *Builder) Build() (*Inventory, error) {
 		}
 	}
 
-	if b.generateInstructions {
-		r.instructions = generateInstructions(r)
-	}
-
 	return r, nil
 }