Replaced zod-to-json-schema with Zod v4's native toJSONSchema() method
for generating JSON Schema from Zod schemas. This eliminates the need
for an external dependency and leverages Zod v4's new built-in feature.
Changes:
- Updated generateSchema.ts to use z.toJSONSchema() with draft-7 target
- Removed direct dependency on zod-to-json-schema (still exists via MCP SDK)
- Simplified the schema generation process
The generated schema remains compatible with the existing format and
all tooling that depends on it.
