MoldSim MCP demonstrates solid tool design with clear naming conventions, good descriptions, and well-structured input schemas using Zod validation. All 6 tools follow verb_noun naming patterns and have substantive descriptions (194-350 chars average). Parameter schemas are properly typed with Zod constraints. However, the server lacks documented output schemas, error recovery guidance, and tool annotations (readOnlyHint). All tools are read-only but this is not explicitly declared via annotations. The knowledge base query tool relies on embedding models without exposing failure modes or recovery paths. Descriptions could be more concise (several exceed 300 chars) and output structure is not documented, forcing LLMs to infer response format.

• Add readOnlyHint: true annotation to all 6 tool schemas. This signals to MCP clients that these tools are safe to retry and idempotent.
• Document output schemas as structured JSON. E.g., get_material_properties should declare output as { material_id: string, cross_wlf: {...}, pvt: {...}, thermal: {...}, processing: {...}, mechanical: {...} } with descriptions of each property. This enables agents to extract and chain results.
• Add enum constraints for material parameter in tools that accept them. Instead of listing 20 materials in the description, define: material: z.enum(['abs-generic', 'pp-homo', 'pp-copo', 'pa6', 'pa66', 'pa66-gf30', 'pc', 'pc-abs', 'pom', 'hdpe', 'ldpe', 'pmma', 'pbt', 'pbt-gf30', 'pet', 'ps', 'hips', 'tpu', 'san', 'asa']). This is self-documenting and prevents hallucinated material names.
• Add error recovery guidance to query_simulation_knowledge. Document what happens if the embedding model fails to load, the Qdrant instance is unavailable, or a query times out. Return actionable errors like 'Knowledge base unavailable. Try again in 30 seconds or contact the administrator.'
• Trim descriptions to 150-200 chars. E.g., generate_dfm_checklist: 'Evaluate an injection molded part against 15+ design rules. Returns pass/warn/fail for wall thickness, rib design, undercuts, gates, and surface texture. Requires part description; optional parameters for enhanced accuracy.'
• Add parameter descriptions for gate_type enum values. E.g., '"edge" (part perimeter), "sub" (submarine), "pin" (center pin), "hot" (heated nozzle), "fan" (multiple flow paths), "tunnel" (moving core)' instead of just listing the strings.