Elasticsearch Knowledge Graph for MCP

create_entities

Add entities to a knowledge graph memory zone, including names, types, and observations, to enhance data storage and retrieval in Elasticsearch-based AI systems.

Instructions

Create entities in knowledge graph (memory)

Input Schema

TableJSON Schema

Name	Required	Description	Default
`entities`	Yes	List of entities to create
`memory_zone`	Yes	Memory zone to create entities in.

Implementation Reference

src/index.ts:752-824 (handler)

Handler for create_entities tool: validates no existing entities with same name in the zone, then saves each new entity using kgClient.saveEntity and returns the created entities.

else if (toolName === "create_entities") {
  const entities = params.entities;
  const zone = params.memory_zone;
  
  // First, check if any entities already exist or have empty names
  const conflictingEntities = [];
  const invalidEntities = [];
  
  for (const entity of entities) {
    // Check for empty names
    if (!entity.name || entity.name.trim() === '') {
      invalidEntities.push({
        name: "[empty]",
        reason: "Entity name cannot be empty"
      });
      continue;
    }
    
    const existingEntity = await kgClient.getEntity(entity.name, zone);
    if (existingEntity) {
      conflictingEntities.push(entity.name);
    }
  }
  
  // If there are conflicts or invalid entities, reject the operation
  if (conflictingEntities.length > 0 || invalidEntities.length > 0) {
    const zoneMsg = zone ? ` in zone "${zone}"` : "";
    
    // Fetch existing entity details if there are conflicts
    const existingEntitiesData = [];
    if (conflictingEntities.length > 0) {
      for (const entityName of conflictingEntities) {
        const existingEntity = await kgClient.getEntity(entityName, zone);
        if (existingEntity) {
          existingEntitiesData.push(existingEntity);
        }
      }
    }
    
    return formatResponse({
      success: false,
      error: `Entity creation failed${zoneMsg}, no entities were created.`,
      conflicts: conflictingEntities.length > 0 ? conflictingEntities : undefined,
      existingEntities: existingEntitiesData.length > 0 ? existingEntitiesData : undefined,
      invalidEntities: invalidEntities.length > 0 ? invalidEntities : undefined,
      message: conflictingEntities.length > 0 ? 
        "Feel free to extend existing entities with more information if needed, or create entities with different names. Use update_entities to modify existing entities." : 
        "Please provide valid entity names for all entities."
    });
  }
  
  // If no conflicts, proceed with entity creation
  const createdEntities = [];
  for (const entity of entities) {
    const savedEntity = await kgClient.saveEntity({
      name: entity.name,
      entityType: entity.entityType,
      observations: entity.observations,
      relevanceScore: entity.relevanceScore ?? 1.0
    }, zone);
    
    createdEntities.push(savedEntity);
  }
  
  return formatResponse({
    success: true,
    entities: createdEntities.map(e => ({
      name: e.name,
      entityType: e.entityType,
      observations: e.observations
    }))
  });
}

src/kg-client.ts:143-194 (helper)

Core implementation of entity creation: initializes zone index, handles upsert logic by preserving timestamps if entity exists, indexes the entity document into Elasticsearch.

async saveEntity(
  entity: Omit<ESEntity, 'type' | 'readCount' | 'lastRead' | 'lastWrite' | 'zone'>, 
  zone?: string,
  options?: {
    validateZones?: boolean;
  }
): Promise<ESEntity> {
  // Validate entity name is not empty
  if (!entity.name || entity.name.trim() === '') {
    throw new Error('Entity name cannot be empty');
  }
  
  const actualZone = zone || this.defaultZone;
  await this.initialize(actualZone);

  // Default to true for zone validation
  const validateZones = options?.validateZones ?? true;
  
  // Validate that zone exists if required
  if (validateZones && actualZone !== this.defaultZone) {
    const zoneExists = await this.zoneExists(actualZone);
    if (!zoneExists) {
      throw new Error(`Cannot create entity: Zone '${actualZone}' does not exist. Create the zone first.`);
    }
  }

  const now = new Date().toISOString();
  const existingEntity = await this.getEntity(entity.name, actualZone);
  
  const newEntity: ESEntity = {
    type: 'entity',
    name: entity.name,
    entityType: entity.entityType,
    observations: entity.observations || [],
    // If entity exists, preserve its readCount and lastRead, but update lastWrite
    readCount: existingEntity?.readCount ?? 0,
    lastRead: existingEntity?.lastRead ?? now,
    lastWrite: now,
    relevanceScore: entity.relevanceScore ?? (existingEntity?.relevanceScore ?? 1.0),
    zone: actualZone
  };

  const indexName = this.getIndexForZone(actualZone);
  await this.client.index({
    index: indexName,
    id: `entity:${entity.name}`,
    document: newEntity,
    refresh: true // Make sure it's immediately available for search
  });

  return newEntity;
}

src/index.ts:168-200 (schema)

JSON schema definition for create_entities tool input: requires array of entities (each with name, entityType, optional observations) and memory_zone.

{
  name: "create_entities",
  description: "Create entities in knowledge graph (memory)",
  inputSchema: {
    type: "object",
    properties: {
      entities: {
        type: "array",
        items: {
          type: "object",
          properties: {
            name: {type: "string", description: "Entity name"},
            entityType: {type: "string", description: "Entity type"},
            observations: {
              type: "array", 
              items: {type: "string"},
              description: "Observations about this entity"
            }
          },
          required: ["name", "entityType"]
        },
        description: "List of entities to create"
      },
      memory_zone: {
        type: "string",
        description: "Memory zone to create entities in."
      }
    },
    required: ["entities", "memory_zone"],
    additionalProperties: false,
    "$schema": "http://json-schema.org/draft-07/schema#"
  }
},

src/index.ts:89-649 (registration)

Registers the create_entities tool in the list of available tools returned by ListToolsRequestSchema handler.

server.setRequestHandler(ListToolsRequestSchema, async () => {
  return {
    tools: [
      {
        name: "inspect_files",
        description: "Agent driven file inspection that uses AI to retrieve relevant content from multiple files.",
        inputSchema: {
          type: "object",
          properties: {
            file_paths: {
              type: "array",
              items: { type: "string" },
              description: "Paths to the files (or directories) to inspect"
            },
            information_needed: {
              type: "string",
              description: "Full description of what information is needed from the files, including the context of the information needed. Do not be vague, be specific. The AI agent does not have access to your context, only this \"information needed\" and \"reason\" fields. That's all it will use to decide that a line is relevant to the information needed. So provide a detailed specific description, listing all the details about what you are looking for."
            },
            reason: {
              type: "string",
              description: "Explain why this information is needed to help the AI agent give better results. The more context you provide, the better the results will be."
            },
            include_lines: {
              type: "boolean",
              description: "Whether to include the actual line content in the response, which uses more of your limited token quota, but gives more informatiom (default: false)"
            },
            keywords: {
              type: "array",
              items: { type: "string" },
              description: "Array of specific keywords related to the information needed. AI will target files that contain one of these keywords. REQUIRED and cannot be null or empty - the more keywords you provide, the better the results. Include variations, synonyms, and related terms."
            }
          },
          required: ["file_paths", "information_needed", "include_lines", "keywords"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "inspect_knowledge_graph",
        description: "Agent driven knowledge graph inspection that uses AI to retrieve relevant entities and relations based on a query.",
        inputSchema: {
          type: "object",
          properties: {
            information_needed: {
              type: "string",
              description: "Full description of what information is needed from the knowledge graph, including the context of the information needed. Do not be vague, be specific. The AI agent does not have access to your context, only this \"information needed\" and \"reason\" fields. That's all it will use to decide that an entity is relevant to the information needed."
            },
            reason: {
              type: "string",
              description: "Explain why this information is needed to help the AI agent give better results. The more context you provide, the better the results will be."
            },
            include_entities: {
              type: "boolean",
              description: "Whether to include the full entity details in the response, which uses more of your limited token quota, but gives more information (default: false)"
            },
            include_relations: {
              type: "boolean",
              description: "Whether to include the entity relations in the response (default: false)"
            },
            keywords: {
              type: "array",
              items: { type: "string" },
              description: "Array of specific keywords related to the information needed. AI will target entities that match one of these keywords. REQUIRED and cannot be null or empty - the more keywords you provide, the better the results. Include variations, synonyms, and related terms."
            },
            memory_zone: {
              type: "string",
              description: "Memory zone to search in. If not provided, uses the default zone."
            },
            entity_types: {
              type: "array",
              items: { type: "string" },
              description: "Optional filter to specific entity types"
            }
          },
          required: ["information_needed", "keywords"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "create_entities",
        description: "Create entities in knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            entities: {
              type: "array",
              items: {
                type: "object",
                properties: {
                  name: {type: "string", description: "Entity name"},
                  entityType: {type: "string", description: "Entity type"},
                  observations: {
                    type: "array", 
                    items: {type: "string"},
                    description: "Observations about this entity"
                  }
                },
                required: ["name", "entityType"]
              },
              description: "List of entities to create"
            },
            memory_zone: {
              type: "string",
              description: "Memory zone to create entities in."
            }
          },
          required: ["entities", "memory_zone"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "update_entities",
        description: "Update entities in knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            entities: {
              type: "array",
              description: "List of entities to update",
              items: {
                type: "object",
                properties: {
                  name: {type: "string"},
                  entityType: {type: "string"},
                  observations: {
                    type: "array",
                    items: {type: "string"}
                  },
                  isImportant: {type: "boolean"}
                },
                required: ["name"]
              }
            },
            memory_zone: {
              type: "string",
              description: "Memory zone specifier. Entities will be updated in this zone."
            }
          },
          required: ["entities", "memory_zone"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "delete_entities",
        description: "Delete entities from knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            names: {
              type: "array",
              items: {type: "string"},
              description: "Names of entities to delete"
            },
            memory_zone: {
              type: "string",
              description: "Memory zone specifier. Entities will be deleted from this zone."
            },
            cascade_relations: {
              type: "boolean",
              description: "Whether to delete relations involving these entities (default: true)",
              default: true
            }
          },
          required: ["names", "memory_zone"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "create_relations",
        description: "Create relationships between entities in knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            relations: {
              type: "array",
              description: "List of relations to create",
              items: {
                type: "object",
                properties: {
                  from: {type: "string", description: "Source entity name"},
                  fromZone: {type: "string", description: "Optional zone for source entity, defaults to memory_zone or default zone. Must be one of the existing zones."},
                  to: {type: "string", description: "Target entity name"},
                  toZone: {type: "string", description: "Optional zone for target entity, defaults to memory_zone or default zone. Must be one of the existing zones."},
                  type: {type: "string", description: "Relationship type"}
                },
                required: ["from", "to", "type"]
              }
            },
            memory_zone: {
              type: "string",
              description: "Optional default memory zone specifier. Used if a relation doesn't specify fromZone or toZone."
            },
            auto_create_missing_entities: {
              type: "boolean",
              description: "Whether to automatically create missing entities in the relations (default: true)",
              default: true
            }
          },
          required: ["relations"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "delete_relations",
        description: "Delete relationships from knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            relations: {
              type: "array",
              description: "List of relations to delete",
              items: {
                type: "object",
                properties: {
                  from: {type: "string", description: "Source entity name"},
                  to: {type: "string", description: "Target entity name"},
                  type: {type: "string", description: "Relationship type"}
                },
                required: ["from", "to", "type"]
              }
            },
            memory_zone: {
              type: "string",
              description: "Optional memory zone specifier. If provided, relations will be deleted from this zone."
            }
          },
          required: ["relations"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "search_nodes",
        description: "Search entities using ElasticSearch query syntax. Supports boolean operators (AND, OR, NOT), fuzzy matching (~), phrases (\"term\"), proximity (\"terms\"~N), wildcards (*, ?), and boosting (^N). Examples: 'meeting AND notes', 'Jon~', '\"project plan\"~2'. All searches respect zone isolation.",
        inputSchema: {
          type: "object",
          properties: {
            query: {
              type: "string",
              description: "ElasticSearch query string."
            },
            informationNeeded: {
              type: "string",
              description: "Important. Describe what information you are looking for, to give a precise context to the search engine AI agent. What questions are you trying to answer? Helps get more useful results."
            },
            reason: {
              type: "string",
              description: "Explain why this information is needed to help the AI agent give better results. The more context you provide, the better the results will be."
            },
            entityTypes: {
              type: "array",
              items: {type: "string"},
              description: "Filter to specific entity types (OR condition if multiple)."
            },
            limit: {
              type: "integer",
              description: "Max results (default: 20, or 5 with observations)."
            },
            sortBy: {
              type: "string",
              enum: ["relevance", "recency", "importance"],
              description: "Sort by match quality, access time, or importance."
            },
            includeObservations: {
              type: "boolean",
              description: "Include full entity observations (default: false).",
              default: false
            },
            memory_zone: {
              type: "string",
              description: "Limit search to specific zone. Omit for default zone."
            },
          },
          required: ["query", "memory_zone", "informationNeeded", "reason"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "open_nodes",
        description: "Get details about specific entities in knowledge graph (memory) and their relations",
        inputSchema: {
          type: "object",
          properties: {
            names: {
              type: "array",
              items: {type: "string"},
              description: "Names of entities to retrieve"
            },
            memory_zone: {
              type: "string",
              description: "Optional memory zone to retrieve entities from. If not specified, uses the default zone."
            }
          },
          required: ["names", "memory_zone"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "add_observations",
        description: "Add observations to an existing entity in knowledge graph (memory)",
        inputSchema: {
          type: "object",
          properties: {
            name: {
              type: "string",
              description: "Name of entity to add observations to"
            },
            observations: {
              type: "array",
              items: {type: "string"},
              description: "Observations to add to the entity"
            },
            memory_zone: {
              type: "string",
              description: "Optional memory zone where the entity is stored. If not specified, uses the default zone."
            }
          },
          required: ["memory_zone", "name", "observations"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "mark_important",
        description: "Mark entity as important in knowledge graph (memory) by boosting its relevance score",
        inputSchema: {
          type: "object",
          properties: {
            name: {
              type: "string",
              description: "Entity name"
            },
            important: {
              type: "boolean",
              description: "Set as important (true - multiply relevance by 10) or not (false - divide relevance by 10)"
            },
            memory_zone: {
              type: "string",
              description: "Optional memory zone specifier. If provided, entity will be marked in this zone."
            },
            auto_create: {
              type: "boolean",
              description: "Whether to automatically create the entity if it doesn't exist (default: false)",
              default: false
            }
          },
          required: ["memory_zone", "name", "important"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "get_recent",
        description: "Get recently accessed entities from knowledge graph (memory) and their relations",
        inputSchema: {
          type: "object",
          properties: {
            limit: {
              type: "integer",
              description: "Max results (default: 20 if includeObservations is false, 5 if true)"
            },
            includeObservations: {
              type: "boolean",
              description: "Whether to include full entity observations in results (default: false)",
              default: false
            },
            memory_zone: {
              type: "string",
              description: "Optional memory zone to get recent entities from. If not specified, uses the default zone."
            }
          },
          required: ["memory_zone"],
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "list_zones",
        description: "List all available memory zones with metadata. When a reason is provided, zones will be filtered and prioritized based on relevance to your needs.",
        inputSchema: {
          type: "object",
          properties: {
            reason: {
              type: "string",
              description: "Reason for listing zones. What zones are you looking for? Why are you looking for them? The AI will use this to prioritize and filter relevant zones."
            }
          },
          additionalProperties: false,
          "$schema": "http://json-schema.org/draft-07/schema#"
        }
      },
      {
        name: "create_zone",
        description: "Create a new memory zone with optional description.",
        inputSchema: {
          type: "object",
          properties: {
            name: {
              type: "string",
              description: "Zone name (cannot be 'default')"
            },
            shortDescription: {
              type: "string",
              description: "Short description of the zone."
            },
            description: {
              type: "string",
              description: "Full zone description. Make it very descriptive and detailed."
            }
          },
          required: ["name"]
        }
      },
      {
        name: "delete_zone",
        description: "Delete a memory zone and all its entities/relations.",
        inputSchema: {
          type: "object",
          properties: {
            name: {
              type: "string",
              description: "Zone name to delete (cannot be 'default')"
            },
            confirm: {
              type: "boolean",
              description: "Confirmation flag, must be true",
              default: false
            }
          },
          required: ["name", "confirm"]
        }
      },
      {
        name: "copy_entities",
        description: "Copy entities between zones with optional relation handling.",
        inputSchema: {
          type: "object",
          properties: {
            names: {
              type: "array",
              items: { type: "string" },
              description: "Entity names to copy"
            },
            source_zone: {
              type: "string",
              description: "Source zone"
            },
            target_zone: {
              type: "string",
              description: "Target zone"
            },
            copy_relations: {
              type: "boolean",
              description: "Copy related relationships (default: true)",
              default: true
            },
            overwrite: {
              type: "boolean",
              description: "Overwrite if entity exists (default: false)",
              default: false
            }
          },
          required: ["names", "source_zone", "target_zone"]
        }
      },
      {
        name: "move_entities",
        description: "Move entities between zones (copy + delete from source).",
        inputSchema: {
          type: "object",
          properties: {
            names: {
              type: "array",
              items: { type: "string" },
              description: "Entity names to move"
            },
            source_zone: {
              type: "string",
              description: "Source zone"
            },
            target_zone: {
              type: "string",
              description: "Target zone"
            },
            move_relations: {
              type: "boolean",
              description: "Move related relationships (default: true)",
              default: true
            },
            overwrite: {
              type: "boolean",
              description: "Overwrite if entity exists (default: false)",
              default: false
            }
          },
          required: ["names", "source_zone", "target_zone"]
        }
      },
      {
        name: "merge_zones",
        description: "Merge multiple zones with conflict resolution options.",
        inputSchema: {
          type: "object",
          properties: {
            source_zones: {
              type: "array",
              items: { type: "string" },
              description: "Source zones to merge from"
            },
            target_zone: {
              type: "string",
              description: "Target zone to merge into"
            },
            delete_source_zones: {
              type: "boolean",
              description: "Delete source zones after merging",
              default: false
            },
            overwrite_conflicts: {
              type: "string",
              enum: ["skip", "overwrite", "rename"],
              description: "How to handle name conflicts",
              default: "skip"
            }
          },
          required: ["source_zones", "target_zone"]
        }
      },
      {
        name: "zone_stats",
        description: "Get statistics for entities and relationships in a zone.",
        inputSchema: {
          type: "object",
          properties: {
            zone: {
              type: "string",
              description: "Zone name (omit for default zone)"
            }
          },
          required: ["zone"]
        }
      },
      {
        name: "get_time_utc",
        description: "Get the current UTC time in YYYY-MM-DD hh:mm:ss format",
        inputSchema: {
          type: "object",
          properties: {},
          additionalProperties: false
        }
      }
    ]
  };
});

Tool Definition Quality

C2.9/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries full burden but only states the basic action without behavioral details. It doesn't disclose permissions needed, whether creation is idempotent, error handling, or rate limits, which are critical for a write operation in a knowledge graph system.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence with no wasted words, clearly front-loading the core action. It's appropriately sized for the tool's complexity, making it easy to parse quickly.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of a write operation in a knowledge graph with no annotations and no output schema, the description is incomplete. It lacks details on behavioral traits, error cases, or return values, leaving significant gaps for an agent to operate effectively.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents both parameters ('entities' and 'memory_zone') thoroughly. The description adds no additional meaning beyond the schema, such as explaining what a 'memory_zone' represents or constraints on entity creation, meeting the baseline for high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Create') and resource ('entities in knowledge graph (memory)'), making the purpose understandable. However, it doesn't differentiate from siblings like 'update_entities' or 'add_observations', which would require specifying this is for initial creation only.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives. For example, it doesn't mention whether to use 'update_entities' for modifying existing entities or 'add_observations' for adding observations to existing entities, leaving the agent without context for tool selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Install Server

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MCP directory API

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