This MCP server provides 10 tools for querying ClinicalTrials.gov. While tool names follow verb_noun conventions and the schema structures are present, there are significant gaps in parameter descriptions, output documentation, and error handling guidance. Most tools lack comprehensive descriptions of their return values and error scenarios. Parameter descriptions are minimal or absent in several tools. The server implements basic middleware (logging, rate limiting) but does not guide LLMs on recovery strategies or actionable error messages.

• Add comprehensive output schema documentation to each tool showing field names, types, and purposes. For search_clinical_trials, explicitly document that it returns NCT_IDs usable by get_study_details.
• Expand discovery tool descriptions (get_field_metadata, get_search_areas, get_enum_values) with hints like: 'Call this first to discover valid field names before using the fields parameter in search_clinical_trials or get_study_details.'
• Document error scenarios and recovery paths: 'If NCT_ID is invalid (not found), try searching by condition/term first. If rate limit is hit (429), wait 60 seconds before retrying.'
• Add enum or format constraints for the 'fields' parameter. Either list valid field names as an enum or state 'See get_field_metadata for available fields.'
• Document pagination behavior: 'Default page_size=10, max 100. page_token is opaque; request the next page by passing the token from the previous response. When page_token is null, all results have been retrieved.'
• State result limits in search_clinical_trials description: 'Returns up to <N> studies per page. Use page_token for pagination to fetch all matching results.'
• Add parameter descriptions to tools with empty input schemas (e.g., get_field_metadata, get_search_areas). Document what data structure is returned and the typical use case.
• Include timestamps, count, and next_cursor in paginated responses to enable robust pagination. Document whether results are sorted and by what field.

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

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