ChainFETCH MCP Server presents 12 well-structured tools with complete JSON Schema definitions and consistent naming conventions. However, the implementation exhibits significant gaps in parameter descriptions, output schema documentation, and error handling guidance. All tools follow verb_noun naming (search_*, get_*), and all have input schemas with type definitions. Descriptions are present but vary in quality, most are 80-150 characters (within the 10-1024 baseline) but lack actionable context about when to use each tool or what downstream actions are possible. Critical gaps: (1) No output schemas are documented anywhere in the code, forcing LLMs to infer response structure; (2) 150+ and 254+ parameter search tools expose only a handful of parameters in the schema, creating a false sense of completeness; (3) Error handling appears minimal, no evidence of recovery guidance, retryability classification, or actionable error messages; (4) No tool annotations (readOnlyHint, destructiveHint, idempotentHint) despite all tools being read-only operations. Parameter descriptions are inconsistent, some are bare field names ('Transaction hash', 'Block hash') while others include constraints ('default: 10, max: 50'). The server demonstrates competent baseline quality (all schemas present, naming correct, basic structure sound) but lacks the polish and LLM-optimization needed for production confidence.

• Add explicit output schemas for all 12 tools. Document the structure of results returned by each endpoint, including field names, types, and which fields are suitable for downstream tool calls. Example: search_addresses_semantic should document that results include {address: string, balance: string, transaction_count: integer, ...} so the LLM knows which fields to extract for get_address_info.
• Standardize parameter names across related tools: rename get_address_info's 'address' parameter to 'address_hash' to match get_address_summary, and rename get_transaction_info's 'transaction' to 'transaction_hash' to match get_transaction_summary. This reduces LLM confusion when chaining calls.
• Add tool annotations to the tool definitions in the ListToolsRequest handler. Add 'readOnlyHint: true' to all 12 tools to signal that they are safe to retry and do not require confirmation. The SDK supports this via the ToolDefinition interface.
• Enhance descriptions for semantic search tools. Clarify that semantic_search is for natural language queries ('I want to find Ethereum whales'), JSON search is for structured filtering ('Find all contracts with >1000 transactions'), and LLM search is for complex intent parsing. Add 1-2 sentences per tool explaining when to use it instead of the alternatives.
• Remove example values from parameter descriptions (e.g., 'in ETH, e.g., "1.5"', 'e.g., "10.0"'). Replace with formal constraints: eth_balance_min should have minLength/maxLength or pattern constraints, not examples. Enums are preferred where applicable.