TMDL Authoring for Power BI

What it does

This skill provides detailed technical guidance for directly editing and authoring TMDL files within Power BI Project (PBIP) structures. It enables agents to modify semantic models (measures, columns, tables, and relationships) as text files, which is critical for Git-based version control and collaboration.

When to use it

Activate this skill when the user needs to edit .tmdl files directly, add or modify DAX measures in TMDL format, update object descriptions using the triple-slash (///) syntax, or convert BIM files to TMDL. It is specifically intended as a fallback when higher-level tools like Tabular Editor CLI or the Power BI MCP server are unavailable.

What's included

• References: Comprehensive guides on object properties, naming conventions, and TMDL file examples.
• Instructions: Strict rules on semantic indentation, name quoting, and the critical distinction between description comments (///) and regular comments (//).
• Patterns: Quality patterns for summarizeBy settings and formatString definitions.

Compatible agents

Designed for agents with file-system access and text-editing capabilities, specifically targeted at Claude Code and GitHub Copilot.