AgentPay MCP exhibits significant definition quality gaps. Tool descriptions are present but often vague and marketing-focused rather than LLM-optimized. Input schemas are visible but lack proper type definitions and constraints. Critical issues: (1) descriptions like 'Usage-vetted pick of the best x402 provider' and 'Hard multi-call spend cap with a verifiable receipt ledger' are cryptic and assume domain knowledge; (2) many parameters lack type constraints (e.g., 'min_amount' in whale_activity is a string with no format/range guidance); (3) no output schemas documented; (4) duplicate tool names (gas_tracker appears twice); (5) no error handling guidance; (6) parameters like 'need' in verified_route are dangerously open-ended. The server reads as a domain-specific payment/trading tool, but definitions prioritize marketing language over LLM clarity.

• Rewrite descriptions to be LLM-optimized (50 - 200 chars, action-focused). Example: 'verified_route' → 'Find the most cost-effective data provider for your query. Returns provider name, endpoint, and estimated cost. Use when you need external data and want to minimize spend.'
• Add output schema documentation for every tool. Example for session_create: 'Returns {session_id: string, max_spend_usdc: string, network: string, created_at: ISO8601, receipt_url: string}'. This enables chaining.
• Replace free-form string parameters with enums or patterns. 'need' in verified_route should be an enum (e.g., 'price_feed', 'market_data', 'on_chain_analytics'). 'min_amount' should specify units and range (e.g., 'Minimum transfer amount in USDC (0.01 - 1000000)').
• Remove or rename the duplicate 'gas_tracker' tool. Keep one canonical version with a clear description of what it returns (gas prices, network congestion, estimated fees, etc.).
• Add error recovery hints to descriptions. Example: 'If token not found, try searching by contract address or check token_market_data() for available pairs.' This guides LLM self-correction.