feat: slim tool responses (#141)

Reduce token usage by slimming tool responses. Instead of returning full Gitea SDK objects (with nested user/repo objects, avatars, permissions, etc.), each operation now has a colocated `slim.go` that extracts only the fields an LLM needs. List endpoints return even fewer fields than single-item endpoints.

Other changes:
- Add `params` helpers to DRY parameter extraction across 40+ handlers
- Remove `{"Result": ...}` wrapper for flatter responses
- Reduce default pageSize from 100 to 30

Fixes: https://gitea.com/gitea/gitea-mcp/issues/128

*Created by Claude on behalf of @silverwind*

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/141
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

operation/user/slim.go

@@ -0,0 +1,42 @@
+package user
+
+import (
+	gitea_sdk "code.gitea.io/sdk/gitea"
+)
+
+func slimUserDetail(u *gitea_sdk.User) map[string]any {
+	if u == nil {
+		return nil
+	}
+	return map[string]any{
+		"id":         u.ID,
+		"login":      u.UserName,
+		"full_name":  u.FullName,
+		"email":      u.Email,
+		"avatar_url": u.AvatarURL,
+		"html_url":   u.HTMLURL,
+		"is_admin":   u.IsAdmin,
+	}
+}
+
+func slimOrg(o *gitea_sdk.Organization) map[string]any {
+	if o == nil {
+		return nil
+	}
+	return map[string]any{
+		"id":          o.ID,
+		"name":        o.Name,
+		"full_name":   o.FullName,
+		"description": o.Description,
+		"avatar_url":  o.AvatarURL,
+		"website":     o.Website,
+	}
+}
+
+func slimOrgs(orgs []*gitea_sdk.Organization) []map[string]any {
+	out := make([]map[string]any, 0, len(orgs))
+	for _, o := range orgs {
+		out = append(out, slimOrg(o))
+	}
+	return out
+}

operation/user/slim_test.go

@@ -0,0 +1,39 @@
+package user
+
+import (
+	"testing"
+
+	gitea_sdk "code.gitea.io/sdk/gitea"
+)
+
+func TestSlimUserDetail(t *testing.T) {
+	u := &gitea_sdk.User{
+		ID:        42,
+		UserName:  "alice",
+		FullName:  "Alice Smith",
+		Email:     "alice@example.com",
+		AvatarURL: "https://gitea.com/avatars/42",
+		HTMLURL:   "https://gitea.com/alice",
+		IsAdmin:   true,
+	}
+	m := slimUserDetail(u)
+
+	if m["id"] != int64(42) {
+		t.Errorf("expected id 42, got %v", m["id"])
+	}
+	if m["login"] != "alice" {
+		t.Errorf("expected login alice, got %v", m["login"])
+	}
+	if m["full_name"] != "Alice Smith" {
+		t.Errorf("expected full_name Alice Smith, got %v", m["full_name"])
+	}
+	if m["is_admin"] != true {
+		t.Errorf("expected is_admin true, got %v", m["is_admin"])
+	}
+}
+
+func TestSlimUserDetail_Nil(t *testing.T) {
+	if m := slimUserDetail(nil); m != nil {
+		t.Errorf("expected nil for nil user, got %v", m)
+	}
+}

operation/user/user.go

@@ -24,7 +24,7 @@ const (
 	// defaultPage is the default starting page number used for paginated organization listings.
 	defaultPage = 1
 	// defaultPageSize is the default number of organizations per page for paginated queries.
-	defaultPageSize = 100
+	defaultPageSize = 30
 )
 
 // Tool is the MCP tool manager instance for registering all MCP tools in this package.
@@ -66,16 +66,6 @@ func registerTools() {
 	}
 }
 
-// getIntArg parses an integer argument from the MCP request arguments map.
-// Returns def if missing, not a number, or less than 1. Used for pagination arguments.
-func getIntArg(req mcp.CallToolRequest, name string, def int) int {
-	v := params.GetOptionalInt(req.GetArguments(), name, int64(def))
-	if v < 1 {
-		return def
-	}
-	return int(v)
-}
-
 // GetUserInfoFn is the handler for "get_my_user_info" MCP tool requests.
 // Logs invocation, fetches current user info from gitea, wraps result for MCP.
 func GetUserInfoFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
@@ -88,7 +78,7 @@ func GetUserInfoFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolR
 	if err != nil {
 		return to.ErrorResult(fmt.Errorf("get user info err: %v", err))
 	}
-	return to.TextResult(user)
+	return to.TextResult(slimUserDetail(user))
 }
 
 // GetUserOrgsFn is the handler for "get_user_orgs" MCP tool requests.
@@ -96,8 +86,7 @@ func GetUserInfoFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolR
 // performs Gitea organization listing, and wraps the result for MCP.
 func GetUserOrgsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 	log.Debugf("[User] Called GetUserOrgsFn")
-	page := getIntArg(req, "page", defaultPage)
-	pageSize := getIntArg(req, "pageSize", defaultPageSize)
+	page, pageSize := params.GetPagination(req.GetArguments(), defaultPageSize)
 
 	opt := gitea_sdk.ListOrgsOptions{
 		ListOptions: gitea_sdk.ListOptions{
@@ -113,5 +102,5 @@ func GetUserOrgsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolR
 	if err != nil {
 		return to.ErrorResult(fmt.Errorf("get user orgs err: %v", err))
 	}
-	return to.TextResult(orgs)
+	return to.TextResult(slimOrgs(orgs))
 }