feat: replace server instructions with skill resources

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),
 	}
@@ -125,6 +124,9 @@ func NewMCPServer(ctx context.Context, cfg *MCPServerConfig, deps ToolDependenci
 		registerDynamicTools(ghServer, inv, deps, cfg.Translator)
 	}
 
+	// Register skill resources for MCP clients that support skills-based discovery.
+	RegisterSkillResources(ghServer)
+
 	return ghServer, nil
 }
 

pkg/github/skill_resources_test.go

@@ -0,0 +1,84 @@
+package github
+
+import (
+	"testing"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAllSkillsCoverAllToolsets(t *testing.T) {
+	// Collect all tool names from AllTools
+	allToolNames := make(map[string]bool)
+	for _, tool := range AllTools(stubTranslator) {
+		allToolNames[tool.Tool.Name] = true
+	}
+
+	// Collect all tool names covered by skills
+	coveredTools := make(map[string]bool)
+	for _, skill := range allSkills() {
+		for _, toolName := range skill.allowedTools {
+			coveredTools[toolName] = true
+		}
+	}
+
+	// Every tool should be covered by at least one skill
+	for toolName := range allToolNames {
+		assert.True(t, coveredTools[toolName], "tool %q is not covered by any skill", toolName)
+	}
+}
+
+func TestBuildSkillContent(t *testing.T) {
+	skill := skillDefinition{
+		name:         "test-skill",
+		description:  "A test skill",
+		allowedTools: []string{"tool_a", "tool_b"},
+		body:         "# Test\n\nUse these tools.\n",
+	}
+
+	content := buildSkillContent(skill)
+
+	assert.Contains(t, content, "---\n")
+	assert.Contains(t, content, "name: test-skill\n")
+	assert.Contains(t, content, "description: A test skill\n")
+	assert.Contains(t, content, "  - tool_a\n")
+	assert.Contains(t, content, "  - tool_b\n")
+	assert.Contains(t, content, "# Test\n")
+}
+
+func TestSkillResourceURIs(t *testing.T) {
+	skills := allSkills()
+	require.NotEmpty(t, skills)
+
+	uris := make(map[string]bool)
+	names := make(map[string]bool)
+
+	for _, skill := range skills {
+		uri := "skill://github/" + skill.name + "/SKILL.md"
+
+		assert.False(t, uris[uri], "duplicate skill URI: %s", uri)
+		uris[uri] = true
+
+		assert.False(t, names[skill.name], "duplicate skill name: %s", skill.name)
+		names[skill.name] = true
+
+		assert.NotEmpty(t, skill.description, "skill %s has empty description", skill.name)
+		assert.NotEmpty(t, skill.allowedTools, "skill %s has no allowed tools", skill.name)
+		assert.NotEmpty(t, skill.body, "skill %s has empty body", skill.name)
+	}
+}
+
+func TestRegisterSkillResources(t *testing.T) {
+	server := mcp.NewServer(&mcp.Implementation{
+		Name:    "test-server",
+		Version: "0.0.1",
+	}, nil)
+
+	// Should not panic
+	RegisterSkillResources(server)
+
+	// Verify the expected number of skills were registered by counting definitions
+	skills := allSkills()
+	assert.Equal(t, 27, len(skills), "expected 27 workflow-oriented skills")
+}

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",
@@ -44,21 +43,20 @@ var (
 	ToolsetMetadataGit = inventory.ToolsetMetadata{
 		ID:          "git",
 		Description: "GitHub Git API related tools for low-level Git operations",
+		Default:     true,
 		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",
@@ -69,58 +67,67 @@ var (
 	ToolsetMetadataOrgs = inventory.ToolsetMetadata{
 		ID:          "orgs",
 		Description: "GitHub Organization related tools",
+		Default:     true,
 		Icon:        "organization",
 	}
 	ToolsetMetadataActions = inventory.ToolsetMetadata{
 		ID:          "actions",
 		Description: "GitHub Actions workflows and CI/CD operations",
+		Default:     true,
 		Icon:        "workflow",
 	}
 	ToolsetMetadataCodeSecurity = inventory.ToolsetMetadata{
 		ID:          "code_security",
 		Description: "Code security related tools, such as GitHub Code Scanning",
+		Default:     true,
 		Icon:        "codescan",
 	}
 	ToolsetMetadataSecretProtection = inventory.ToolsetMetadata{
 		ID:          "secret_protection",
 		Description: "Secret protection related tools, such as GitHub Secret Scanning",
+		Default:     true,
 		Icon:        "shield-lock",
 	}
 	ToolsetMetadataDependabot = inventory.ToolsetMetadata{
 		ID:          "dependabot",
 		Description: "Dependabot tools",
+		Default:     true,
 		Icon:        "dependabot",
 	}
 	ToolsetMetadataNotifications = inventory.ToolsetMetadata{
 		ID:          "notifications",
 		Description: "GitHub Notifications related tools",
+		Default:     true,
 		Icon:        "bell",
 	}
 	ToolsetMetadataDiscussions = inventory.ToolsetMetadata{
-		ID:               "discussions",
-		Description:      "GitHub Discussions related tools",
-		Icon:             "comment-discussion",
-		InstructionsFunc: generateDiscussionsToolsetInstructions,
+		ID:          "discussions",
+		Description: "GitHub Discussions related tools",
+		Default:     true,
+		Icon:        "comment-discussion",
 	}
 	ToolsetMetadataGists = inventory.ToolsetMetadata{
 		ID:          "gists",
 		Description: "GitHub Gist related tools",
+		Default:     true,
 		Icon:        "logo-gist",
 	}
 	ToolsetMetadataSecurityAdvisories = inventory.ToolsetMetadata{
 		ID:          "security_advisories",
 		Description: "Security advisories related tools",
+		Default:     true,
 		Icon:        "shield",
 	}
 	ToolsetMetadataProjects = inventory.ToolsetMetadata{
-		ID:               "projects",
-		Description:      "GitHub Projects related tools",
-		Icon:             "project",
-		InstructionsFunc: generateProjectsToolsetInstructions,
+		ID:          "projects",
+		Description: "GitHub Projects related tools",
+		Default:     true,
+		Icon:        "project",
 	}
 	ToolsetMetadataStargazers = inventory.ToolsetMetadata{
 		ID:          "stargazers",
 		Description: "GitHub Stargazers related tools",
+		Default:     true,
 		Icon:        "star",
 	}
 	ToolsetMetadataDynamic = inventory.ToolsetMetadata{
@@ -131,6 +138,7 @@ var (
 	ToolsetLabels = inventory.ToolsetMetadata{
 		ID:          "labels",
 		Description: "GitHub Labels related tools",
+		Default:     true,
 		Icon:        "tag",
 	}
 

pkg/github/tools_test.go

@@ -8,6 +8,28 @@ import (
 )
 
 func TestAddDefaultToolset(t *testing.T) {
+	allDefaultToolsets := []string{
+		"actions",
+		"code_security",
+		"context",
+		"copilot",
+		"dependabot",
+		"discussions",
+		"gists",
+		"git",
+		"issues",
+		"labels",
+		"notifications",
+		"orgs",
+		"projects",
+		"pull_requests",
+		"repos",
+		"secret_protection",
+		"security_advisories",
+		"stargazers",
+		"users",
+	}
+
 	tests := []struct {
 		name     string
 		input    []string
@@ -19,42 +41,19 @@ func TestAddDefaultToolset(t *testing.T) {
 			expected: []string{"actions", "gists"},
 		},
 		{
-			name:  "default keyword present - expand and remove default",
-			input: []string{"default"},
-			expected: []string{
-				"context",
-				"copilot",
-				"repos",
-				"issues",
-				"pull_requests",
-				"users",
-			},
+			name:     "default keyword present - expand and remove default",
+			input:    []string{"default"},
+			expected: allDefaultToolsets,
 		},
 		{
-			name:  "default with additional toolsets",
-			input: []string{"default", "actions", "gists"},
-			expected: []string{
-				"actions",
-				"gists",
-				"context",
-				"copilot",
-				"repos",
-				"issues",
-				"pull_requests",
-				"users",
-			},
+			name:     "default with additional toolsets",
+			input:    []string{"default", "actions", "gists"},
+			expected: allDefaultToolsets,
 		},
 		{
-			name:  "default with overlapping toolsets - should not duplicate",
-			input: []string{"default", "context", "repos"},
-			expected: []string{
-				"context",
-				"copilot",
-				"repos",
-				"issues",
-				"pull_requests",
-				"users",
-			},
+			name:     "default with overlapping toolsets - should not duplicate",
+			input:    []string{"default", "context", "repos"},
+			expected: allDefaultToolsets,
 		},
 		{
 			name:     "empty input",