Server has 9 well-named, read-only tools with complete input schemas and descriptions. Naming follows verb_noun pattern (query_, get_, list_). All tools have 50-200 char descriptions and typed parameters with descriptions. However, output schemas are not documented in the source, LLMs cannot predict return structure. Error handling is minimal (basic try/except returning {"error": str(e)}). No enum constraints on string parameters like sort_by, sort_order, granularity, mode. Parameters lack range/format constraints (e.g., limit unbounded, date formats not validated). No pagination guidance in descriptions despite limit parameters. Missing idempotent/readOnly annotations. Composition is sound, tools are single-purpose and chainable via IDs.

• Document output schemas for all tools. Example: query_email_database returns {"results": [{"id": string, "subject": string, "from": string, "date": ISO8601, ...}], "total": integer, "cursor": string|null}. Use JSON Schema format.
• Add enum constraints to string parameters. sort_by: enum ["message_count", "latest_date", ...]; sort_order: enum ["asc", "desc"]; granularity: enum ["day", "week", "month", "year"]; mode: enum ["full", "summary", "key_points"].
• Add min/max bounds to numeric parameters. limit: integer, minimum 1, maximum 100; snippet_length: integer, minimum 50, maximum 5000; max_messages: integer, minimum 1, maximum 500.
• Enhance error handling with actionable messages. Instead of {"error": "Email not found"}, return {"error": "Email ID 'abc123' not found. Try query_email_database() to search by subject or sender."}. Categorize as retryable vs fatal.
• Add readOnlyHint: true to all tool definitions in the MCP server registration. This signals to agents that these tools are safe to call without side effects.