Critical gaps across all dimensions. Tool definitions lack proper JSON Schema with type information, only string type names are visible in the handshake, not structured schemas. Parameter descriptions are missing entirely (only parameter names shown). Tool descriptions are present but minimal (10-20 chars). No output schema documented. No error handling guidance. No input validation hints. The code shows a basic MCP handshake but tool registration is incomplete and does not follow production patterns.

• Define input schemas as proper JSON Schema objects with 'type', 'description', and constraints. Example: {'query': {'type': 'string', 'description': 'Gmail search query (e.g., from:[email protected] subject:urgent)', 'minLength': 1, 'maxLength': 256}}.
• Expand tool descriptions to 100-200 chars. For searchEmails: 'Search Gmail inbox for emails matching a query string. Returns up to 20 matching email summaries with IDs, sender, subject, and date. Use this to find emails before reading full content with readEmail.'
• Add parameter descriptions. For 'query': 'Gmail search query string (e.g., from:[email protected], subject:invoice, has:attachment). See Gmail search operators documentation.' For 'emailId': 'The unique Gmail message ID returned by searchEmails. Required to fetch full email content.'
• Document output schemas in tool descriptions or as a separate schema field. Example: searchEmails returns [{emailId, from, subject, date, snippet}]; readEmail returns {emailId, from, to, subject, date, body, attachments}.
• Add error handling with recovery hints. Example: 'If searchEmails returns no results, try a simpler query (e.g., just a sender email). If readEmail fails with 'Invalid emailId', call searchEmails first to get valid IDs.'

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

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry