A requirement the spck.dev suite checks on UCP servers. The quoted text is the normative requirement; the citation links to the exact line of the pinned spec source it was taken from.
A conforming catalog MCP transport implementation MUST implement JSON-RPC 2.0 correctly, validate tool inputs against UCP schemas, support cursor-based pagination with a default limit of 10, and return -32602 (Invalid params) for requests exceeding batch size limits (the catalog MCP conformance list beyond the Lookup-tool exposure that MCP-001 covers).
A deviation on a MUST fails the run and shows the requirement next to the actual response. Checks the suite cannot validate soundly are reported inconclusive or not-tested — never a silent pass. The full verdict semantics are on the grading rubric.
The hosted check covers the read-only surface; the CLI and GitHub Action run the full suite, including this check when your store declares the capability it belongs to.