Update lib documentation

**Description**
Currently lib lacks proper filtering support.

**Proposed solution**
Add configurable filtering with sensible defaults.

**Priority**: Low/Medium

The issue does not name a file, test, or entry point. Start by locating the lib filtering path in the Shell-based terminal agent, then determine how configurable filtering and its defaults should be represented; done means filtering works with sensible defaults and can be configured.

Written by the indexing model from the issue text.