Server has 21 tools with consistent naming (verb_noun pattern) and basic schemas. However, descriptions are generic and lack LLM-optimization guidance. Parameter descriptions exist but are minimal (avg ~40 chars, below 72-char baseline). Output schemas are not documented. Error handling is absent, no recovery guidance, no categorization. Security concern: OAuth tokens stored in environment without explicit secret-injection pattern documentation. Resource definitions present but tool composition could be tighter (e.g., gmail_send_message and gmail_modify_message are separate when they could be unified with optional parameters).

• Document output schemas for all tools. For gmail_list_messages, specify: {messages: [{id, threadId, from, subject, date}], total_count, next_cursor}. This enables LLMs to chain tools correctly.
• Expand parameter descriptions to 80 - 150 chars. E.g., 'Maximum number of messages to return (1 - 100, default 10). Use pagination to retrieve more than 100 messages without hitting API limits.'
• Add error recovery guidance to tool descriptions. E.g., 'If message not found, call gmail_list_messages() with a search query to locate the message ID.'
• Remove or implement drive_upload_file. If unimplemented, delete it to prevent LLM confusion. If implementing, document the actual file handling mechanism.
• Add pagination support: return next_cursor and total_count in list tools. Document in descriptions: 'Use next_cursor to fetch the next page of results.'