PayFlowAgent MCP defines 6 tools with consistent naming (verb_noun pattern: score_token, decide_token, screen_tokens, yield_opportunities) and detailed descriptions in German. All tools have input schemas with type definitions and regex patterns for token addresses. However, output schemas are completely undocumented, the server provides no structured response definitions, forcing LLMs to infer result shapes. Parameter descriptions are present but lack actionable constraint details (e.g., 'Max. Anzahl Token (1-25, Default 10)' is present but could be clearer on why these bounds exist). Error handling is minimal, no recovery guidance or error categorization visible in the code. Tool composition is sound (each tool has one responsibility), but the lack of output documentation and error patterns significantly limits production readiness.

• Document output schemas for all tools. Define the structure of score, riskLevel, action, graduationPct, momentum, reasons[], and any other returned fields. Use JSON Schema or TypeScript interfaces visible in the code.
• Add error handling guidance: 'If token address is invalid (not 0x + 40 hex), the tool returns HTTP 400 with message "Invalid token address". Suggest the user verify the address format.' Categorize errors as retryable (rate limit) vs. user-fixable (invalid input).
• Explain payment behavior: 'Paid tools charge USDC via x402 on Base. Calls are idempotent, retrying with the same parameters will not double-charge. If payment fails, the tool returns HTTP 402 with payment details.'
• Add English descriptions alongside German. Use the pattern: '[German description] / [English description]' or provide separate localized tool definitions.
• Document pagination and result limits. For screen_tokens and yield_opportunities, clarify: 'Results are sorted by score (descending). If more results exist, the response includes a next_cursor field for pagination.'