Server has well-structured tool definitions with clear naming (verb_noun pattern) and comprehensive descriptions (avg 180 chars, within baseline 194). All 5 tools have input schemas with type declarations and parameter descriptions. However, output schemas are not documented, LLMs cannot predict response structure for chaining. Error handling is minimal (only connection_required and HTTP status codes returned). No enum constraints on folder/search parameters. Missing idempotency guidance and confirmation patterns for read-only operations.

• Document output schemas for all tools. Add a 'returns' field to each tool definition specifying field names, types, and structure. Example: outlook_list_messages returns { value: Array<{ id, subject, from, receivedDateTime, bodyPreview, isRead, hasAttachments }> }.
• Add enum constraint to folder parameter: enum: ['inbox', 'sentitems', 'drafts', 'deleteditems', 'archive', 'junk'] with description 'Well-known folder name or folder ID from outlook_list_folders.'
• Enhance error responses with actionable guidance. Return { error: 'connection_required', message: '...', action: 'Connect your Microsoft 365 account at https://pipeworx.io/account' } and { error: 'invalid_folder', message: '...', action: 'Call outlook_list_folders() to see available folders.' }.
• Add pagination to outlook_list_messages and outlook_search_messages. Return { value: [...], total: N, nextCursor: '...' } and accept offset/cursor parameter. Document in descriptions: 'Returns up to 25 results; use nextCursor to fetch more.'
• Implement and expose the transport layer (HTTP+SSE or Streamable HTTP). Add server initialization code that registers tools via MCP protocol and handles request/response serialization.