NEXUS Engine provides 6 tools with detailed descriptions (avg ~180 chars, within baseline 194), but critical gaps in schema visibility and parameter documentation. Tool names follow verb_noun convention (add_, update_, delete_, search_, get_, graph_). Descriptions are substantive and include domain context, rate limits, and permission requirements. However, input schemas are inferred from the brief parameter lists provided, no explicit JSON Schema definitions are visible in the source code excerpt. Parameters lack type declarations, constraints (enums, ranges), and format specifications. Output schemas are undocumented. Error handling is mentioned (rate limits, org suspension blocks) but recovery guidance is absent. Security posture is strong (permission gates, audit mentions, soft-delete), but parameter validation rules are not visible.

• Add explicit JSON Schema definitions for all tool inputs. For add_memory, declare domain as enum: {type: 'string', enum: ['memory', 'knowledge', 'guideline', 'skill']}. For search_memory, declare limit as {type: 'integer', minimum: 1, maximum: 100, default: 20}.
• Document output schemas for all tools. E.g., search_memory returns {chunks: [{id, content, snippet, score}], distilled_response: string, total_count: integer, next_cursor?: string}. This enables LLMs to chain calls and extract fields.
• Enhance error messages with recovery guidance. Instead of 'Rate limit exceeded', return 'Rate limit exceeded (120 queries/min). Retry after 30 seconds or reduce query complexity.' For 'Org suspended', return 'Organization is suspended. Contact support at [email protected].'
• Add parameter constraints to descriptions. E.g., 'content (string, max 256 KB): text of the memory to save. Must not exceed 256,000 bytes.' For limit: 'limit (integer, 1 - 100, default 20): max results to return.'
• Implement a confirm_delete_memory tool or add a dry_run parameter to delete_memory. Return a confirmation token that must be passed to a separate confirm_delete call. This prevents accidental data loss from agent mistakes.