Eight read-only tools with consistent naming (verb_noun pattern: etsy_search_*, etsy_get_*) and complete input schemas. All tools have descriptions (avg 95 chars) and typed parameters with descriptions. However, output schemas are not documented, responses are JSON envelopes with generic 'data' fields, forcing LLMs to infer structure. Error handling returns JSON with 'ok' flag and error messages, but lacks recovery guidance (e.g., 'try search_listings first'). No tool annotations (readOnlyHint, idempotentHint). Parameter descriptions are adequate but lack format constraints (e.g., 'period' accepts '7d', '30d', '90d' but no enum or pattern). Date parameters (date_from, date_to) lack ISO 8601 format hints in descriptions.

• Document output schemas for all tools. Add a 'Returns' section to each tool docstring specifying the structure of the 'data' field (e.g., 'data.results: array of listing objects with fields: listing_id, title, price, shop_id, ...').
• Add tool annotations via FastMCP. Mark all tools with readOnlyHint=true and idempotentHint=true to signal to LLMs that they are safe to retry and compose without side effects.
• Enhance error messages with recovery guidance. When validation fails, return 'Invalid status: got "pending", must be one of: open, unshipped, unpaid, completed, processing, all' instead of bare error text.
• Formalize parameter constraints. Convert 'status' description values to an enum in the schema; add a pattern or enum for 'period' (e.g., pattern: '^\d+d$', enum: ['7d', '30d', '90d', '365d']).
• Add per-item error handling for paginated results. If etsy_search_orders or etsy_get_active_listings encounters a partial failure, return successful items with a 'partial_failure' flag and error details for failed items, rather than failing entirely.