[Java] `@CopilotTool` ergonomics: lambda: Create implementation plan: ignorance reduction

[edburns]

Iterating at: https://github.com/github/copilot-sdk/tree/edburns/1810-java-tool-ergonomics-tool-as-lambda

See plan: https://github.com/github/copilot-sdk/blob/edburns/1810-java-tool-ergonomics-tool-as-lambda/1810-java-tool-ergonomics-tool-as-lambda-remove-before-merge/1810-ignorance-reduction-for-implementation-plan.md