The response schemas added yesterday made every paginated list tool fail. The
plugin's fields are documented as OpenAPI format and validated with a JSON
Schema validator, and `nullable: true` is not a JSON Schema keyword — so it is
ignored, `type: string` is enforced, and `previous: null` on the first page is
rejected as *null is not of type "string"*.
The failure lands after the backend has already done the work, surfaces to the
caller as a bare tool retry exhaustion, and appears nowhere in the gateway's own
logs. Found only because an orchestrating agent asked a question that paged.
The generator now rewrites `nullable: true` into `type: [T, "null"]` wherever it
inlines a schema, request bodies included. A 3.1 spec needs none of this.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Produced by k8s-platform/tools/generate-mcp-tools.py: deck file openapi2mcp
does the conversion, and the wrapper re-injects the five things Kong's
generator cannot emit — per-tool ACLs, the MCP behavioural annotations, the
response schemas the plugin uses for structuredOutput, the real upstream host,
and JSON-only request bodies. Each is a documented gap; see
k8s-platform/MCP-TOOL-GENERATION.md.
tools-policy.yaml carries the ACLs and doubles as the allow-list: an operation
becomes a tool only if the policy names it. Kong would otherwise expose every
operation in the spec, DELETE included, and can express no authorization at all
from a bearer-token spec — silently, exit 0, no warning.
Same tools as before, same ACLs. What changed: query parameters are now
declared and callable, each tool carries its response schema so calls return
structured content instead of raw JSON, and request bodies are no longer
tripled across three identical content types.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>