[feature] Specify parameter values for one Trial

/kind feature

**Describe the solution you'd like**
[A clear and concise description of what you want to happen.]

**Anything else you would like to add:**
[Miscellaneous information that will assist in solving the issue.]

The issue does not identify any files, tests, entry points, or concrete behavior to inspect. Clarify how parameter values should be specified for one Trial and define the expected API or configuration behavior and acceptance tests before implementation.

Written by the indexing model from the issue text.