The OLS MCP server provides 4 well-named tools with consistent naming conventions (verb_noun pattern: search_, get_). Tool descriptions are present and reasonably detailed (80-150 characters), providing context for when and why to use each tool. Input schemas are fully declared with proper JSON Schema types. However, there are significant gaps in parameter descriptions, output schema documentation, and error handling guidance. No parameter descriptions exist for most inputs, which violates the critical pattern that every parameter needs a description explaining what it controls. Output schemas are not documented anywhere in the provided code, making it unclear what fields agents should expect from each tool. The code snippet is truncated, preventing complete visibility into implementation details.

• Add non-empty descriptions to every input parameter. For 'ontology_id': 'The OLS identifier for the ontology (e.g., "go", "uberon", "chebi"). This is the internal system ID used by OLS, distinct from the ontology name.' Include format hints for complex identifiers like IRIs.
• Document complete output schemas for each tool. Example for search_all_ontologies: 'Returns a list of ontology term matches, each containing: {"iri": string (unique identifier), "label": string (human-readable term name), "ontology_id": string (parent ontology ID), "description": string or null, "score": number (search relevance, 0-1)}. Always returns at least 0 items, up to max_results.'
• Standardize parameter naming across related tools. Use 'ontology_id' consistently (not 'ontology') and explicitly document that 'ontology_iri' is distinct (a full URI vs a short ID). This prevents agents from passing wrong identifier types.
• Enhance pagination documentation. Clarify: 'Currently returns up to max_results items per call. If more results exist, future versions will support cursor-based pagination via next_cursor field (coming soon). For now, no way to fetch beyond max_results.' This sets expectations.
• Add error handling guidance in descriptions. Example: 'If ontology_id is not found, returns error with message "Unknown ontology: <id>. Try search_all_ontologies() with an empty query to list available ontologies."'
• Validate parameter constraints early and explicitly. For numeric params (max_results, page_size), add min/max ranges to descriptions and schemas: 'Integer between 1 and 100. Defaults to 20.' Helps agents self-correct.