This Solana MCP server has consistent tool naming and reasonable descriptions, but exhibits critical gaps in schema documentation, parameter specifications, and error handling. Of the 11 tools, only 2 have input schemas visible in the provided code (wallet_address, token parameters). Most tools lack formally defined JSON schemas with type constraints, and parameter descriptions are present but minimal (average ~60 chars, below the 72-char baseline). Output schemas are completely undocumented, the LLM has no visibility into what fields each tool returns. The server uses FastMCP, which should auto-generate schemas from Python type hints, but the actual Pydantic models are not shown in the source excerpt, making it impossible to verify schema quality. Descriptions are generally clear but generic; they lack the actionable context needed for LLM tool selection (e.g., 'when to use this vs. similar tools', dependencies, error recovery paths). No error handling guidance is visible. All tools are READ_ONLY (good), but no tool annotations (readOnlyHint, idempotentHint) are declared. The server is well-organized with clear module structure, but definition quality lags behind production baselines.

• Document output schemas for all 11 tools. For each, explicitly list fields, types, and meanings. Example: 'Returns: {balance_sol: float (SOL amount), tokens: [{mint: string, amount: float, usd_value: float}], total_usd: float}'.
• Convert all parameter constraints to JSON Schema. For 'limit' parameters, add maximum and minimum to the schema, not just descriptions. For 'sort_by', use enum: ['apr', 'tvl', 'volume'].
• Add error handling guidance to each tool description. Pattern: 'If [external service] is unavailable or times out, [retry with backoff / ask user to retry / return partial results]. Common errors: [list specific ones].'
• Declare readOnlyHint: true for all tools in the tool registration (FastMCP @mcp.tool() decorator or direct tool registration call). This signals to MCP clients that these tools cannot modify state.
• Standardize tool descriptions to English. Non-English descriptions harm LLM tool selection and reduce discoverability. Translate all German descriptions to English.
• Add 'When to use this vs. similar tools' to descriptions. For example, compare get_token_price (current price) vs. get_token_info (metadata) vs. check_token_safety (risk assessment) so LLM picks the right one.
• Document pagination strategy in tools returning lists (get_transaction_history, get_defi_yields, get_whale_transactions). Add 'offset', 'cursor', or 'page' parameter with example usage.
• Clarify token parameter format. Add: 'token: string, Solana token symbol (e.g., 'SOL', 'BONK', 'JUP') OR 32-character mint address (base58). Either format accepted.'

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry