fix: preserve full workspace MCP tool input schemas from agent to coderd - #28377
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fix: preserve full workspace MCP tool input schemas from agent to coderd#28377ibetitsmike wants to merge 1 commit into
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The workspace MCP path lost schema fidelity twice: the agent kept only type, properties, and required before proto encoding, and coderd re-split the pushed proto Struct into a properties map plus required list for the tool wrapper. Keys such as $defs, $ref, additionalProperties, and combinators never reached the provider. Pass the schema map through the agent whole (the proto Struct already carries arbitrary JSON objects), add MCPToolInfo.InputSchema for the complete schema alongside the flattened Schema/Required pair, and let WorkspaceMCPTool expose it through FullInputSchema so the chatloop wire path prefers it. Old agents push the reduced schema, which is itself a valid schema, so the same path serves both payload generations without version detection.
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The workspace MCP path lost tool schema fidelity twice: the workspace agent kept only
type,properties, andrequiredbefore proto encoding (agentmcp.toolInputSchemaMap), and coderd re-split the pushed protoStructinto a properties map plus required list for the tool wrapper (splitMCPInputSchema). Keys such as$defs,$ref,additionalProperties, and combinators never reached the provider.google.protobuf.Structalready carries arbitrary JSON objects, so no proto change is needed.workspacesdk.MCPToolInfogains anInputSchemafield for the complete schema. The flattenedSchema/Requiredpair stays populated with today's semantics for existing consumers.WorkspaceMCPToolstores the full schema and exposes it throughFullInputSchema(), so the chatloop wire path from the previous PR prefers it.Old agents push the reduced
{type, properties, required}schema, which is itself a valid JSON Schema, so the same code path serves both payload generations without version detection. Payloads with no schema at all fall back to reconstruction fromInfo().Stack Context
Top of a stack that fixes MCP tool input-schema loss end to end: below, the
properties: nullfix and the chatd-side full-schema passthrough for external MCP and dynamic tools.