What you can ask

One example per tool, in the order a first session usually goes (list, plan, look at rows if needed, check, create, describe, query):

list_workspaces — "Which Fabric workspaces can I see?"
list_sources — "List the data sources in the demo workspace."
list_tables — "Which tables are in demo_lh, schema shop?"
plan_backend — "Plan a backend over demo_lh, schema shop." — nothing is deployed; you get keys, relationships, the rule for each, ambiguous columns, suggested composite keys and an ER diagram. "Treat order_id plus line_no as the key of order_items" passes keys.
sample_rows — "Show me a few rows of orders." — when a column's meaning is unclear before deciding on keys.
validate_plan — "Check the plan against the data." — every key counted for uniqueness and NULLs, every relationship for orphans; the example on /check shows what the answer looks like.
create_backend — "Create it as shop_api." — creates the API for GraphQL item, or updates it in place if the name exists.
describe_backend — "What can I query in shop_api?" — the types, fields and relationship names a query uses.
query_graphql — "Using shop_api, which customers ordered a trail bike in October?" — a read-only query; relationships nest.
rayfin_connector — "Generate Rayfin connector entities for it." — TypeScript entity classes for Fabric Apps.
ontology_draft — "Draft a Fabric IQ ontology from demo_lh." — entity types, keys and relationship types with their rules, ready to import.
compare_semantic_model — "Compare our Sales model with the plan for demo_lh." — what the model lacks, what a rule or the data contradicts, and the measures it could add.
gold_views_draft — "Draft gold views for demo_lh, schema shop." — one materialized lake view per fact table over the silver tables, with data quality rules.
export_item_definitions — "Export what you would create, in Fabric's Git format." — the item folders to commit to your own repository.
review_plan — "Keep this review as a file: accept ship_to_id as the ship-to address, leave audit_log without a key, and run the checks." — a file to commit next to your code; next time, "Read back krusgraph-review.demo-lh.shop.json and tell me what changed."

Five first questions on a lakehouse nobody has documented (each is useful on its own):

"Read demo_lh, schema shop, as a graph: which tables are facts, which are dimensions, and what are the subject areas?" (analyze_schema)
"Plan the keys and relationships for schema shop and tell me which rule made each one." (plan_backend)
"Check that plan against the data: are the keys unique and do the references hold?" (validate_plan)
"Which columns look like they should point at another table but are in no relationship?" (suggest_relationships)
"Write the data dictionary for schema shop." (data_dictionary; dbt_schema when the team tests with dbt)