🐛 Bug-fix PR

Closes #2172

📌 Summary

Fixes a bug where a single entity with corrupted data would cause the entire listing operation to fail. When convert_*_to_read functions encountered invalid data (e.g., malformed JSON in auth_value, missing required fields), the exception would propagate up and return a 500 error instead of gracefully returning the valid entities.

🔁 Reproduction Steps

Issue: Parsing failures in entity conversion stops entire listing

1. Have a tool/resource/prompt with corrupted data in the database (e.g., invalid JSON in auth_value field)
2. Call any listing endpoint (/admin/tools, /tools/list, etc.)
3. Before fix: 500 Internal Server Error - entire listing fails
4. After fix: 200 OK - valid entities returned, corrupted entity skipped with error logged

🐞 Root Cause

The convert_*_to_read functions (e.g., convert_tool_to_read, convert_resource_to_read, convert_prompt_to_read) were called without exception handling in listing loops. When Pydantic validation failed for any single entity, the exception would bubble up and abort the entire operation.

Affected locations:

• mcpgateway/services/tool_service.py - list_tools, list_server_tools, list_tools_for_user
• mcpgateway/services/resource_service.py - resource listing methods
• mcpgateway/services/prompt_service.py - prompt listing methods
• mcpgateway/routers/admin.py - admin API endpoints

💡 Fix Description

Wrapped all convert_*_to_read calls in try-except blocks to handle conversion failures gracefully:

# Before
for tool in tools:
    result.append(convert_tool_to_read(tool))

# After
for tool in tools:
    try:
        result.append(convert_tool_to_read(tool))
    except Exception as e:
        logger.error(f"Failed to convert tool {tool.id} ({getattr(tool, 'name', 'unknown')}): {e}")
        continue

Key design points:

• Failed conversions are logged with entity ID and name for debugging
• Loop continues processing remaining valid entities
• No change to return type or API contract
• Added comprehensive unit and e2e tests to verify graceful handling

🧪 Verification

📐 MCP Compliance (if relevant)

• Matches current MCP spec
• No breaking change to MCP clients

✅ Checklist

• Code formatted (make black isort pre-commit)
• No secrets/credentials committed