tool-cordis: cordis_define plugin param uses oneOf; some LLM providers stringify it, causing permanent validation failure

[long-safe-accont-4567-uvwxyz-9876]

Bug: cordis_define fails with oneOf on the plugin parameter

Summary

The cordis_define tool (packages/extensions/tool-cordis) defines its plugin parameter as a oneOf union of two object schemas. Some LLM providers (reproduced with the PI-AI provider) serialize the value of a parameter whose schema uses oneOf into a JSON string instead of a nested object. Because every oneOf branch expects an object, argument validation always fails:

"plugin" must match exactly one oneOf branch (matched 0)

This makes dynamic Cordis plugin registration impossible under those providers.

Evidence (from session log)

Every tool/call event for cordis_define showed plugin as a string, not an object:

typeof plugin: string
plugin: "{"kind": "new", "idPrefix": "agn"}"

Meanwhile other object parameters on the same tool (e.g. code) stayed objects. So the stringification is triggered specifically by the oneOf schema.

Affected code

packages/extensions/tool-cordis/src/index.ts (~line 160):

plugin: { required: true, oneOf: [ ... ] }

Suggested fix (verified locally)

Replace the oneOf union with a plain object schema plus an enum on kind, and validate the required branch fields in execute:

plugin: { required: true, type: 'object', additionalProperties: false, properties: { kind: { type: 'string', enum: ['new', 'existing'], required: true }, idPrefix: { type: 'string' }, pluginId: { type: 'string' } } }

In execute, branch on args.plugin.kind and throw a clear error when the required idPrefix (new) or pluginId (existing) is missing. This compiles clean and, after restarting the host, lets cordis_define validate and register plugins successfully.

Environment

• HEAD: 47f9438 (master)
• No upstream fix exists at the time of this report.

Happy to open a PR with the fix if useful.

[zoahdev]

Landed your fix as a cherry-pick-ready branch:

zoahdev/deepseek-harness@fix/cordis-define-oneof-provider-stringify

plugin is now a plain object schema (kind enum + optional idPrefix/pluginId) and the required branch field is validated in execute. The oneOf stringification from PI-AI is now moot. tool-cordis suite 11/11.

Good catch on the root cause — oneOf parameter schemas getting serialized to a JSON string by some providers is a nasty provider-compat trap that would keep breaking any tool that uses it.