Generate server instructions in the Inventory

internal/ghmcp/server.go

@@ -124,7 +124,8 @@ func NewStdioMCPServer(cfg github.MCPServerConfig) (*mcp.Server, error) {
 		WithDeprecatedAliases(github.DeprecatedToolAliases).
 		WithReadOnly(cfg.ReadOnly).
 		WithToolsets(cfg.EnabledToolsets).
-		WithTools(github.CleanTools(cfg.EnabledTools))
+		WithTools(github.CleanTools(cfg.EnabledTools)).
+		WithServerInstructions()
 		// WithFeatureChecker(createFeatureChecker(cfg.EnabledFeatures))
 
 	// Apply token scope filtering if scopes are known (for PAT filtering)

pkg/github/server.go

@@ -71,18 +71,9 @@ type MCPServerConfig struct {
 type MCPServerOption func(*mcp.ServerOptions)
 
 func NewMCPServer(cfg *MCPServerConfig, deps ToolDependencies, inventory *inventory.Inventory) (*mcp.Server, error) {
-	enabledToolsets := resolveEnabledToolsets(cfg)
 
-	// For instruction generation, we need actual toolset names (not nil).
-	// nil means "use defaults" in inventory, so expand it for instructions.
-	instructionToolsets := enabledToolsets
-	if instructionToolsets == nil {
-		instructionToolsets = GetDefaultToolsetIDs()
-	}
-
-	// Create the MCP server
 	serverOpts := &mcp.ServerOptions{
-		Instructions:      GenerateInstructions(instructionToolsets),
+		Instructions:      inventory.Instructions(),
 		Logger:            cfg.Logger,
 		CompletionHandler: CompletionsHandler(deps.GetClient),
 	}

pkg/github/tools.go

@@ -28,10 +28,11 @@ 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",
+		ID:               "context",
+		Description:      "Tools that provide context about the current user and GitHub context you are operating in",
+		Default:          true,
+		Icon:             "person",
+		InstructionsFunc: generateContextToolsetInstructions,
 	}
 	ToolsetMetadataRepos = inventory.ToolsetMetadata{
 		ID:          "repos",
@@ -45,16 +46,18 @@ var (
 		Icon:        "git-branch",
 	}
 	ToolsetMetadataIssues = inventory.ToolsetMetadata{
-		ID:          "issues",
-		Description: "GitHub Issues related tools",
-		Default:     true,
-		Icon:        "issue-opened",
+		ID:               "issues",
+		Description:      "GitHub Issues related tools",
+		Default:          true,
+		Icon:             "issue-opened",
+		InstructionsFunc: generateIssuesToolsetInstructions,
 	}
 	ToolsetMetadataPullRequests = inventory.ToolsetMetadata{
-		ID:          "pull_requests",
-		Description: "GitHub Pull Request related tools",
-		Default:     true,
-		Icon:        "git-pull-request",
+		ID:               "pull_requests",
+		Description:      "GitHub Pull Request related tools",
+		Default:          true,
+		Icon:             "git-pull-request",
+		InstructionsFunc: generatePullRequestsToolsetInstructions,
 	}
 	ToolsetMetadataUsers = inventory.ToolsetMetadata{
 		ID:          "users",
@@ -93,9 +96,10 @@ var (
 		Icon:        "bell",
 	}
 	ToolsetMetadataDiscussions = inventory.ToolsetMetadata{
-		ID:          "discussions",
-		Description: "GitHub Discussions related tools",
-		Icon:        "comment-discussion",
+		ID:               "discussions",
+		Description:      "GitHub Discussions related tools",
+		Icon:             "comment-discussion",
+		InstructionsFunc: generateDiscussionsToolsetInstructions,
 	}
 	ToolsetMetadataGists = inventory.ToolsetMetadata{
 		ID:          "gists",
@@ -108,9 +112,10 @@ var (
 		Icon:        "shield",
 	}
 	ToolsetMetadataProjects = inventory.ToolsetMetadata{
-		ID:          "projects",
-		Description: "GitHub Projects related tools",
-		Icon:        "project",
+		ID:               "projects",
+		Description:      "GitHub Projects related tools",
+		Icon:             "project",
+		InstructionsFunc: generateProjectsToolsetInstructions,
 	}
 	ToolsetMetadataStargazers = inventory.ToolsetMetadata{
 		ID:          "stargazers",

pkg/github/instructions.go → pkg/github/toolset_instructions.go

@@ -1,75 +1,41 @@
 package github
 
-import (
-	"os"
-	"slices"
-	"strings"
-)
-
-// GenerateInstructions creates server instructions based on enabled toolsets
-func GenerateInstructions(enabledToolsets []string) string {
-	// For testing - add a flag to disable instructions
-	if os.Getenv("DISABLE_INSTRUCTIONS") == "true" {
-		return "" // Baseline mode
-	}
-
-	var instructions []string
+import "github.com/github/github-mcp-server/pkg/inventory"
 
-	// Core instruction - always included if context toolset enabled
-	if slices.Contains(enabledToolsets, "context") {
-		instructions = append(instructions, "Always call 'get_me' first to understand current user permissions and context.")
-	}
-
-	// Individual toolset instructions
-	for _, toolset := range enabledToolsets {
-		if inst := getToolsetInstructions(toolset, enabledToolsets); inst != "" {
-			instructions = append(instructions, inst)
-		}
-	}
+// Toolset instruction functions - these generate context-aware instructions for each toolset.
+// They are called during inventory build to generate server instructions.
 
-	// Base instruction with context management
-	baseInstruction := `The GitHub MCP Server provides tools to interact with GitHub platform.
-
-Tool selection guidance:
-	1. Use 'list_*' tools for broad, simple retrieval and pagination of all items of a type (e.g., all issues, all PRs, all branches) with basic filtering.
-	2. Use 'search_*' tools for targeted queries with specific criteria, keywords, or complex filters (e.g., issues with certain text, PRs by author, code containing functions).
-
-Context management:
-	1. Use pagination whenever possible with batches of 5-10 items.
-	2. Use minimal_output parameter set to true if the full information is not needed to accomplish a task.
-
-Tool usage guidance:
-	1. For 'search_*' tools: Use separate 'sort' and 'order' parameters if available for sorting results - do not include 'sort:' syntax in query strings. Query strings should contain only search criteria (e.g., 'org:google language:python'), not sorting instructions.`
+func generateContextToolsetInstructions(_ *inventory.Inventory) string {
+	return "Always call 'get_me' first to understand current user permissions and context."
+}
 
-	allInstructions := []string{baseInstruction}
-	allInstructions = append(allInstructions, instructions...)
+func generateIssuesToolsetInstructions(_ *inventory.Inventory) string {
+	return `## Issues
 
-	return strings.Join(allInstructions, " ")
+Check 'list_issue_types' first for organizations to use proper issue types. Use 'search_issues' before creating new issues to avoid duplicates. Always set 'state_reason' when closing issues.`
 }
 
-// getToolsetInstructions returns specific instructions for individual toolsets
-func getToolsetInstructions(toolset string, enabledToolsets []string) string {
-	switch toolset {
-	case "pull_requests":
-		pullRequestInstructions := `## Pull Requests
+func generatePullRequestsToolsetInstructions(inv *inventory.Inventory) string {
+	instructions := `## Pull Requests
 
 PR review workflow: Always use 'pull_request_review_write' with method 'create' to create a pending review, then 'add_comment_to_pending_review' to add comments, and finally 'pull_request_review_write' with method 'submit_pending' to submit the review for complex reviews with line-specific comments.`
-		if slices.Contains(enabledToolsets, "repos") {
-			pullRequestInstructions += `
+
+	if inv.HasToolset("repos") {
+		instructions += `
 
 Before creating a pull request, search for pull request templates in the repository. Template files are called pull_request_template.md or they're located in '.github/PULL_REQUEST_TEMPLATE' directory. Use the template content to structure the PR description and then call create_pull_request tool.`
-		}
-		return pullRequestInstructions
-	case "issues":
-		return `## Issues
+	}
+	return instructions
+}
+
+func generateDiscussionsToolsetInstructions(_ *inventory.Inventory) string {
+	return `## Discussions
 
-Check 'list_issue_types' first for organizations to use proper issue types. Use 'search_issues' before creating new issues to avoid duplicates. Always set 'state_reason' when closing issues.`
-	case "discussions":
-		return `## Discussions
-
 Use 'list_discussion_categories' to understand available categories before creating discussions. Filter by category for better organization.`
-	case "projects":
-		return `## Projects
+}
+
+func generateProjectsToolsetInstructions(_ *inventory.Inventory) string {
+	return `## Projects
 
 Workflow: 1) list_project_fields (get field IDs), 2) list_project_items (with pagination), 3) optional updates.
 
@@ -137,7 +103,4 @@ Common Qualifier Glossary (items):
 Never:
    - Infer field IDs; fetch via list_project_fields.
    - Drop 'fields' param on subsequent pages if field values are needed.`
-	default:
-		return ""
-	}
 }