describe_entity

Get detailed information about a specific entity including its measures and dimensions.

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Description

Returns the complete schema of a specific entity, including all available measures, dimensions, and their properties. Use this tool when you need to understand what data an entity contains before writing a query.

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Input Schema

{
  "type": "object",
  "properties": {
    "entityName": {
      "type": "string",
      "description": "Name of the entity to describe (e.g., 'Studies', 'AdverseEvents')"
    }
  },
  "required": ["entityName"]
}

Parameter	Type	Required	Description
entityName	string	Yes	The exact name of the entity (case-insensitive)

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Output

Returns the full entity definition:

Field	Type	Description
name	string	Entity name
title	string	Human-readable title
measures	array	List of available measures
dimensions	array	List of available dimensions
segments	array	Pre-defined filter segments

Measure Properties

Field	Type	Description
name	string	Fully qualified name (e.g., Studies.count)
title	string	Display name
type	string	Measure type (count, sum, avg, etc.)
description	string	What the measure represents

Dimension Properties

Field	Type	Description
name	string	Fully qualified name (e.g., Studies.studyName)
title	string	Display name
type	string	Data type (string, number, time)
description	string	What the dimension represents

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Example

Request

"Describe the AdverseEvents entity"

Tool Call

{
  "tool": "describe_entity",
  "arguments": {
    "entityName": "AdverseEvents"
  }
}

Response

{
  "name": "AdverseEvents",
  "title": "Adverse Events",
  "measures": [
    {
      "name": "AdverseEvents.count",
      "title": "Count",
      "type": "count",
      "description": "Total number of adverse events"
    },
    {
      "name": "AdverseEvents.seriousCount",
      "title": "Serious AE Count",
      "type": "count",
      "description": "Count of serious adverse events"
    },
    {
      "name": "AdverseEvents.relatedCount",
      "title": "Related AE Count",
      "type": "count",
      "description": "Count of drug-related adverse events"
    }
  ],
  "dimensions": [
    {
      "name": "AdverseEvents.aeId",
      "title": "AE ID",
      "type": "string"
    },
    {
      "name": "AdverseEvents.aeTerm",
      "title": "AE Term",
      "type": "string"
    },
    {
      "name": "AdverseEvents.severity",
      "title": "Severity",
      "type": "string"
    },
    {
      "name": "AdverseEvents.causality",
      "title": "Causality",
      "type": "string"
    },
    {
      "name": "AdverseEvents.outcome",
      "title": "Outcome",
      "type": "string"
    },
    {
      "name": "AdverseEvents.onsetDate",
      "title": "Onset Date",
      "type": "time"
    }
  ]
}

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Error Handling

If the entity is not found:

{
  "error": "Entity 'InvalidEntity' not found. Available entities: Studies, Subjects, Sites, AdverseEvents, Enrollments, Visits, VitalSigns, LabTests, Medications, CdiscDm, CdiscAe"
}

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Use Cases

• Query planning: Understand available measures and dimensions before querying
• Schema exploration: Learn what data is available in a specific domain
• Documentation: Generate documentation for data consumers

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Natural Language Examples

You Ask	AI Uses
"What fields are in the Studies entity?"	describe_entity → Studies
"Describe the adverse events data"	describe_entity → AdverseEvents
"What measures can I use for enrollments?"	describe_entity → Enrollments
"Show me the CDISC DM domain schema"	describe_entity → CdiscDm