Powerbi Modeling

Power BI semantic modeling

Connect to the active Power BI semantic model first, inspect its structure, and then provide model-specific guidance or changes for measures, relationships, documentation, RLS, calculation groups, and performance.

When to invoke

• "Create a measure in my Power BI model."
• "Add or fix a relationship and cardinality."
• "Design this as a star schema."
• "Optimize this DAX formula or model performance."
• "Configure RLS or document this semantic model."

Prerequisites and context

• Power BI Modeling MCP Server, often exposed as power-bi-modeling, is required for semantic model inspection and modification. It exposes connection_operations, model_operations, table_operations, column_operations, measure_operations, relationship_operations, dax_query_operations, calculation_group_operations, and security_role_operations.
• Microsoft Learn MCP Server is optional for current documentation research through microsoft_docs_search and microsoft_docs_fetch.

Procedure

1. Connect and analyze before offering guidance:

connection_operations(operation: "ListConnections")
connection_operations(operation: "ListLocalInstances")
model_operations(operation: "Get")
table_operations(operation: "List")
relationship_operations(operation: "List")
measure_operations(operation: "List")

2. If no connection exists, connect to the Desktop or Fabric model before reading or changing metadata.
3. Evaluate model health against star schema, relationships, naming, documentation, measures, hidden fields, date table, RLS, and performance rules.
4. Use bundled references for deeper decisions: references/STAR-SCHEMA.md, references/RELATIONSHIPS.md, references/MEASURES-DAX.md, references/PERFORMANCE.md, and references/RLS.md.
5. Make targeted changes only after model state is known, then validate with metadata reads or DAX validation as appropriate.

Model quality checklist

MCP operation reference

Common modeling tasks

Create a measure with description:

measure_operations(
  operation: "Create",
  definitions: [{
    name: "Total Sales",
    tableName: "Sales",
    expression: "SUM(Sales[Amount])",
    formatString: "$#,##0",
    description: "Sum of all sales amounts"
  }]
)

Update a column description and hide a technical key:

column_operations(
  operation: "Update",
  definitions: [{
    tableName: "Customer",
    name: "CustomerKey",
    description: "Unique identifier for customer dimension",
    isHidden: true
  }]
)

Create a relationship:

relationship_operations(
  operation: "Create",
  definitions: [{
    fromTable: "Sales",
    fromColumn: "CustomerKey",
    toTable: "Customer",
    toColumn: "CustomerKey",
    crossFilteringBehavior: "OneDirection"
  }]
)

Microsoft Learn usage

Use microsoft_docs_search and microsoft_docs_fetch for latest DAX functions, new Power BI features, SCD Type 2 or many-to-many modeling patterns, performance optimization, and security implementation guidance.

Gotchas

• Do not provide generic advice before connecting; always inspect the active model first.
• Do not create bidirectional relationships by default; they can hide ambiguity and performance issues.
• Do not expose technical keys; hide IDs and surrogate keys from report view.
• Do not use calculated columns for business metrics when an explicit measure is appropriate.

Progressive disclosure and bundled resources

• references/STAR-SCHEMA.md: dimension/fact table design and model shape rules.
• references/RELATIONSHIPS.md: relationship cardinality and cross-filter guidance.
• references/MEASURES-DAX.md: DAX measures, naming, and descriptions.
• references/PERFORMANCE.md: optimization and model performance checks.
• references/RLS.md: row-level security implementation patterns.

Output template

## Power BI modeling result

**Status:** complete | needs connection | blocked
**Model:** `<model name or connection>`

### Model observations
| Area | Finding | Recommendation |
| --- | --- | --- |
| Relationships | <finding> | <fix> |

### Changes or proposed changes
| Object | Operation | Definition |
| --- | --- | --- |
| `<measure/table/relationship>` | `<create|update|validate>` | `<details>` |

### Validation
- Connection inspected: <pass|fail>
- DAX validation: <pass|fail|not applicable>
- Metadata re-read: <pass|fail>

Quality gate

• Existing connections or local instances were checked before guidance.
• Model, tables, relationships, and measures were inspected before changes.
• Star schema, naming, descriptions, measures, hidden fields, date table, RLS, and performance were considered as relevant.
• Relationship changes specify cardinality and crossFilteringBehavior.
• Measure changes include expression, table, format string, and description.
• Microsoft Learn research was used for current or complex scenarios when available.