Telemetry — MANDATORY. Every api.fabric.microsoft.com call must carry x-ms-fabric-skill: variable-library-cli (az rest: --headers "x-ms-fabric-skill=variable-library-cli"), including every LRO poll, fabric_lro and retry. Snippets omit it — add it anyway.

CRITICAL NOTES

1. To find the workspace details (including its ID) from a workspace name: list all workspaces, then use JMESPath filtering.
2. To find the item details (including its ID) from a workspace ID, item type, and item name: list all items of that type in that workspace, then use JMESPath filtering.
3. Variable Library has two planes: definition files in Git, and active value set item state in the workspace. Do not treat the active value set as a Git edit. The definition plane is authoring; the item-state plane is operations.
4. Variable Library definition requests must omit the format field entirely. Do not send format: null.
5. Skill disambiguation: use variable-library-cli for every Variable Library concern, including the Variable Library side of a consumer reference. Deep authoring of the consumer item itself belongs elsewhere: pipelines to pipeline-migration, notebooks to spark-cli, Dataflow Gen2 to dataflows-cli, Git lifecycle to git-integration-operations-cli, deployment pipeline mechanics to deployment-pipelines-authoring-cli.
6. Clarify before creating on an underspecified request. If a "set up / create a Variable Library" request does not name the variables, their types, defaults, and value sets, ask a clarifying question or present structured options before creating anything. Do not fabricate a configuration and silently create the item without confirming intent. (A concrete, fully specified request needs no confirmation.)
7. When generating consumer code (notebooks, UDFs) that reads a Boolean Variable Library value, coerce it defensively with str(value).lower() == "true". Never use bool(value) on a string: every non-empty string, including "false", is truthy in Python, so bool("false") is always True.
8. Do not write a value set override whose value equals the variable's default. An override pins the value: once written, later edits to the default no longer reach that value set, so a redundant override silently opts the value set out of inheritance. Omit the override and let the value set inherit. Only override where the value genuinely differs.

Fabric Variable Library -- CLI Skill

This one skill owns Fabric Variable Library items: definitions and value sets, the VL side of consumer references, the active value set item state, and Variable Library CI/CD behavior.

It is a mode dispatcher and contains NO procedures. Pick the mode that matches the request from the table below, then read the matching references/<mode>.md file end to end with your file-reading tool BEFORE issuing a single command. That file holds the endpoints, payload shapes, templates and gotchas; acting without it produces wrong payloads and wrong results.