pay-mcp defines 4 tools with clear verb-noun naming (pay_balance, pay_send, pay_request, pay_history) and reasonable descriptions (100-150 chars each). All tools have input schemas with type definitions and parameter descriptions. However, output schemas are not documented, responses are formatted as text strings rather than structured objects. Parameter descriptions lack format constraints (e.g., address format, amount precision). Error handling is minimal, no guidance on recovery or retry logic. Missing tool annotations (readOnlyHint, destructiveHint) despite clear risk profiles (pay_send is IRREVERSIBLE). No pagination support for pay_history despite accepting a limit parameter.

• Convert text responses to structured JSON objects. pay_send should return {success: boolean, txHash: string, explorerUrl: string, error?: string} instead of markdown. This enables reliable field extraction for chaining.
• Add tool annotations to tool definitions: pay_send needs destructiveHint=true; pay_balance and pay_history need readOnlyHint=true. Update TOOL_DEFINITIONS array to include these hints.
• Document parameter formats in descriptions: address should state '0x-prefixed 42-character hex string'; amount should state 'decimal string with up to 6 decimal places (USDC precision)'.
• Enhance error responses with recovery hints. For insufficient balance: 'Insufficient USDC balance. Current: X, required: Y. Call pay_balance to check available funds.' For invalid address: 'Invalid recipient address. Must be 0x-prefixed 42-character hex string.'
• Add pagination to pay_history: accept offset/limit or cursor parameters; return {transactions: [...], total_count: number, has_more: boolean}. Document max limit (100) in description.