The Pump.fun MCP server provides 6 tools with explicit Zod schema definitions and basic descriptions. All tools are properly registered with the McpServer SDK. However, there are significant gaps in definition quality: (1) Parameter descriptions are minimal and lack detail about formats, ranges, and constraints. For example, 'tokenAddress' is described only as 'The token's mint address' without specifying the format (base58, length) or how to obtain one. (2) Output schemas are not documented, the code returns text responses via createMcpResponse() but no structured schema is declared for what fields clients should expect. (3) Error handling is generic catch-all blocks that return text error messages rather than actionable recovery guidance. (4) No tool annotations (readOnlyHint, destructiveHint, idempotentHint) are present to help agents understand side effects. (5) Tools combining related operations (e.g., buy-token with slippage configuration) lack guidance on parameter relationships and defaults. The average parameter description length is ~40 characters, well below the 72-character baseline for production tools. Overall the server is functional but mediocre, appropriate for early prototyping but not ready for production agent deployments.

• Document output schemas for all tools. Define the structure of responses (e.g., TokenInfo returns {address, name, symbol, market_cap, holder_count, ...}, CreateTokenResult returns {transaction_id, token_address, initial_buy_amount, ...}). Include field types and descriptions so agents can extract needed data.
• Expand parameter descriptions to 100+ characters with explicit constraints. Example: 'tokenAddress (Solana token mint address, base58-encoded 44-character string, e.g., EPjFWaLb3ufWi2pLaKHoXV7Y7WBrvDasg3e4MZvU5Q5Y)' and 'slippageBasisPoints (tolerance in basis points; 100 = 1%, 500 = 5%; must be between 0 and 10000; default 100 is conservative, increase for volatile tokens)'.
• Add tool annotations (destructiveHint, readOnlyHint, idempotentHint) to the server.tool() calls. Example: server.tool('buy-token', ..., {destructiveHint: true, idempotentHint: false}) to signal that repeated calls are unsafe.
• Implement structured error responses with actionable guidance. Example: 'Error: Invalid tokenAddress. Expected base58-encoded 44-character Solana address. Try list-accounts first to see available tokens, or search Pump.fun for the token name.'
• Document parameter constraints in descriptions: specify min/max for numeric fields (e.g., 'initialBuyAmount must be >= 0.0001 SOL and <= 10 SOL'), valid formats for strings, and whether parameters are mutually exclusive.
• Add a discovery tool or extend list-accounts to support pagination (e.g., list-accounts(limit=50, offset=0, total_count) to handle large account lists without flooding the context window.