Three tools with basic schemas and descriptions, but significant gaps in parameter documentation, output schema clarity, and error guidance. Tool names follow verb_noun convention (list_, get_), but descriptions lack actionable context for LLM selection. No parameter descriptions beyond the symbol/date fields. Output schemas are not documented, LLMs cannot plan downstream calls. Error handling returns raw exceptions rather than recovery guidance. Descriptions are 100-150 chars (within baseline 194 avg), but lack WHEN/WHY context. No pagination, no result limits documented, no chaining IDs returned.

• Add explicit output schema documentation to each tool. Example: 'Returns an object with fields: code (string), name (string), symbol (string)' for list_all_currencies. Document what get_currency_rate_details returns (e.g., base, rates object with currency codes as keys).
• Add descriptions to all parameters in inputSchema. For 'symbol', add: 'The ISO 4217 currency code (e.g., USD, EUR, GBP). Call list_all_currencies first to see valid codes.' For 'date', add: 'ISO 8601 date string in YYYY-MM-DD format. Must be a past date; future dates return an error.'
• Enhance tool descriptions with WHEN/WHY context. Example: 'Call this AFTER list_all_currencies to fetch current exchange rates for a specific currency. Returns rates relative to the base currency.' Include what the output contains.
• Implement structured error responses with recovery guidance. Instead of 'Error: Invalid symbol', return 'Invalid currency symbol: got "XYZ". Call list_all_currencies to see valid codes.' Categorize errors as retryable (network timeout) vs user-fixable (invalid symbol).
• Add input validation: validate 'symbol' against known currency codes (cache from list_all_currencies or validate format); validate 'date' format with regex pattern in schema and reject future dates with clear error message.