This server implements 4 Gmail-related tools with explicit tool registration and Zod schemas. However, it suffers from significant definition quality gaps that limit LLM reliability: (1) Tool names lack clear action verbs and are inconsistent in style (gmail-auth vs gmail-thread-snippets); (2) Descriptions are present but generic and lack actionable recovery guidance; (3) Parameter descriptions are minimal; (4) Output schemas are undocumented, the server returns plain text in a 'content' array, but LLMs have no formal specification of what fields/structure to expect; (5) Error handling is basic and does not guide the LLM on recovery steps. The server does have positive signals: tool registration is explicit, input schemas use Zod with type annotations and basic constraints (min/max for days, email format for address), and the code is syntactically sound. Per-tool average is 58, placing this in the lower-fair range.

• Rename tools to follow verb_noun pattern: 'authenticate_gmail', 'list_thread_snippets', 'get_thread_full', 'create_draft_response'. This makes intent clear at a glance.
• Document output schemas formally. Add a comment or separate schema definition specifying the structure of each tool's response, e.g.: { 'type': 'object', 'properties': { 'content': { 'type': 'array', 'items': { 'type': 'object', 'properties': { 'type': { 'type': 'string', 'enum': ['text'] }, 'text': { 'type': 'string' } } } } }.
• Enhance parameter descriptions with dependency hints. E.g., threadId: 'The thread ID (obtain from list_thread_snippets). Required to fetch full message content.'
• Replace generic error messages with actionable recovery guidance. Instead of 'Cannot authenticate gmail now, please try again.', return: 'Authentication failed: session expired. Please call the authenticate_gmail tool to refresh credentials, then retry this request.'
• Add a preview/confirm pattern for gmail-draft-response. Before creating the draft, return a preview with the full message content and ask for confirmation. This prevents accidental drafts.
• Implement pagination for list_thread_snippets. Add optional 'limit' (default 20, max 100) and 'page_token' parameters. Return a next_page_token in the response if more results exist.
• Add tool-chaining documentation. In gmail-thread-full and gmail-draft-response descriptions, explicitly mention which tools must be called first to obtain required parameters.

Inferred effective spec: <=2025-11-25.

• Relies on Stateful initialize / Mcp-Session-Id (removed; protocol is stateless) - make each request self-contained