Summary

Expandind the MCP black-box fitness analysis, adding schema-based action generation, richer coverage objectives, and fault detection.

Changes

• Builds executable MCP tool actions from each tool’s JSON Schema inputSchema.
• Adds coverage objectives for:

1. Tools and resources reached.
2. Successful and failed tool calls.
3. Distinct JSON-RPC outcomes.
4. Resources found or not found.
5. Non-empty resource content.

• Detects MCP-specific faults:

1. Tool internal errors (-32603).
2. Advertised resources that return resource-not-found (-32002).
3. Successful tool results whose structuredContent does not conform to the declared outputSchema.

• Preserves protocol-level JSON-RPC errors in MCP result DTOs and reports detected faults through McpCallResult.

Implementation

HttpMcpClient now parses:

• Tool outputSchema declarations.
• Tool structuredContent as Jackson JsonNode.
• JSON-RPC protocol errors for tool calls and resource reads.

Declared output schemas are compiled once during MCP discovery with networknt’s JSON Schema 2020-12 validator and cached by tool name. Successful tool responses are then validated against the cached schema. Each distinct violation produces a stable SCHEMA_INVALID_RESPONSE fitness target and a detected fault.

External schema references are disabled by default to prevent schemas from initiating network or file requests. They can be enabled explicitly with:

--allowExternalSchemaReferences=true