Bug Summary

When listing tools, resources, prompts, servers, gateways, or A2A agents, if any single entity fails to parse/convert, the entire listing operation fails and returns zero results. This affects both MCP protocol endpoints (/sse, /mcp) and the Admin UI.

Symptoms

• Connecting to gateway with /sse or /mcp returns no tools when any tool has parsing issues
• Admin UI shows tools only up to the point of failure (e.g., stops at 50 tools)
• Pagination controls don't accurately reflect the total number of entities
• No error indication to the user about which entity caused the failure

Root Cause

The entity listing methods iterate over database results and convert each to a read model without per-item error handling:

# Example from tool_service.py:1792-1793
result = []
for s in tools_db:
    result.append(self.convert_tool_to_read(s, include_metrics=False, include_auth=False))

If convert_tool_to_read() raises an exception on any single tool, the loop terminates immediately and no results are returned.

Failure Points in Conversion Methods

For tools specifically (convert_tool_to_read() lines 636-716):

1. decode_auth(tool.auth_value) - AES-GCM decryption failures on corrupted auth
2. base64.b64decode() and string parsing for basic auth credentials
3. next(iter(decoded_auth_value)) - empty dict for authheaders type
4. ToolRead.model_validate(tool_dict) - Pydantic schema validation failures

Similar conversion methods exist for other entity types with their own potential failure points.

Affected Code Locations

Proposed Fix

Wrap each entity conversion in a try-except block to allow partial results and log failures:

result = []
for s in tools_db:
    try:
        result.append(self.convert_tool_to_read(s, include_metrics=False, include_auth=False))
    except Exception as e:
        logger.error(f"Failed to convert tool {getattr(s, 'id', 'unknown')} ({getattr(s, 'name', 'unknown')}): {e}")
        # Continue with remaining tools instead of failing completely

This ensures:

• Users see all valid entities even when some are corrupted
• Errors are logged with entity identification for debugging
• The system degrades gracefully rather than failing completely

Impact

• High: Affects core functionality of tool/resource/prompt discovery
• User-facing: Both API clients and Admin UI users experience silent failures
• Data integrity: Corrupted entities can block access to all other valid entities

Labels

bug, high-priority, services, mcp-protocol, admin-ui