Materials Project MCP has three read-only query tools with clear naming and documented schemas. Tools follow verb_noun naming conventions (get_*, find_*) and are appropriately specific to their domain. Input schemas are fully visible with type declarations. Descriptions are present but generic, they lack context about when to use each tool vs. alternatives, prerequisites, or error recovery guidance. Parameter descriptions are present but minimal (10-30 chars). Output schemas are not documented, forcing LLMs to infer response structure. No error handling guidance or validation rules. The tools are well-composed (each does one thing) and idempotent, but descriptions and output documentation fall short of production standards.

• Document output schemas for all tools. Add a docstring field or example showing the structure: {material_id: string, formula: string, band_gap: float, formation_energy: float, crystal_system: string, space_group: string, density: float, is_stable: bool}.
• Expand tool descriptions from 34 chars to 100-150 chars. Include WHEN to use each tool: 'Find materials that contain specific chemical elements. Use this to search by composition (e.g., iron-oxygen compounds). For materials with a specific chemical formula, use find_materials_by_formula instead.'
• Add element format constraint to get_materials_with_elements: 'elements: List of chemical element symbols (2-letter abbreviations like "Fe", "O", "C"). Elements must be valid periodic table entries. Example: ["Fe", "O"].'
• Specify min/max for numeric parameters: 'max_records: Integer from 1 to 100 (default: 10). Maximum materials to return. Requesting >100 may be slow.'
• Add validation error guidance to tool descriptions: 'Invalid chemical formula. Check spelling and format (e.g., "Fe2O3", not "fe2o3" or "2Fe+3O").'
• Include dependency hints for multi-tool workflows: 'If you only have an element name (e.g., "iron"), convert to the symbol ("Fe") before calling this tool. See periodic table mapping in get_material_details output to verify element symbols.'
• Document what happens when no materials match. Currently unclear if tools return an empty list, error, or null. Specify: 'Returns empty list if no materials match the query.'
• Add pagination guidance if the API supports it. If max_records is a hard cap, note this in the description: 'Results are limited to 10 materials by default. Call again with different element combinations to explore further.'.