Content rule search customization and searcher API documentation

Trying to extend full text search functionality with next requirement: when string like pzInsKey value passed to search string on dev studio (using pega 8.3.0), search result should contain exactly one result with corresponding instance (found by pzInsKey).

1) Tried to pass pzInsKey as parameter to Data-Find-Search.pySearchParams activity, like pyValue = pySearchText, pyName = "pzInsKey", pySection = pySection, similar as described below:

Have only results with All Content option and pzInsKey in "", if picked up rule (in case when rule defined in multiple ruleset/ruleset versions) have same pzInsKey. But this typical behaviour without customization, so I guess it's not working as expected.

2) Second question: where can I found documentation to Searcher API? In Data-Find-Search.pzSearch activity first java step contains method call like below

pega.getSearcherAPI().search(myStepPage, tools.getParameterPage(), tools.getThread());

I want to know which activities, possibly reports launched within this call, and maybe example/advice about described pzInsKey search extension.