Skill catalogs are inverting: the catalog validates, the agent chooses.

AAS Core hit v15.6.0 with 1,993 skills and 44,119 stars, and it explicitly does not rank or recommend. The agent inspects the project, searches the complete local catalog over a read-only stdio MCP server, picks exact skill IDs, and a read-only compose_stack tool validates that selection in memory before the CLI persists it as aas-stack.json and emits an immutable plan for human review. The generalizable shape: give the model complete catalog access plus a validator, not a ranked shortlist, then gate the mutation behind a reviewable artifact. Apply and recovery are still experimental.