Fix remaining linting errors in CI/CD pipeline

The CI/CD pipeline is now working correctly and has identified several linting errors that need to be fixed:

## Linting Errors Found:

1. **errcheck violations**: Multiple instances where error return values are not checked
- `(*encoding/json.Encoder).Encode` errors not checked
- `server.RegisterTool` errors not checked
- Other unspecified error return values not checked

2. **unused code**:
- Function `createJaegerExporter` is unused

3. **ineffassign violations**:
- Ineffectual assignment to `ctx` (multiple instances)

## Action Items:
- [ ] Fix all errcheck violations by properly handling errors
- [ ] Remove unused `createJaegerExporter` function
- [ ] Fix ineffectual assignments to `ctx`
- [ ] Ensure all tests pass after fixes
- [ ] Verify CI/CD pipeline passes all checks

These errors need to be fixed to ensure code quality and enable successful CI/CD runs.