MCP servers providing skills no longer need to expose a skill://index.json resource. The discovery protocol has changed to use a standard skills/list MCP method that supports cursor-based pagination.
Changes:
- Old: MCP server exposes
skill://index.jsonresource with a JSON index of skills (URL-based) - New: MCP server implements the
skills/listmethod, returning pages of skills withurifields and optionaldigestandnextCursor - Pagination is handled automatically — Claude Code iterates until all pages are fetched or limits are reached
- Dropped entries are logged: "N skills/list entries skipped (malformed, missing, or oversized fields)"
- If a page fails mid-pagination, already-fetched entries are used and a warning is logged
If you operate an MCP server that provides skills, update it from the resource-based index to the skills/list method.
Evidence
New discovery function (search for "skills/list failed") and old discovery removed (search for "skill://index.json" — now gone)
Strings lifted out of the shipped bundle, so the claim above can be checked against them.