[Schema] No support for additonalProperties in tool input schema

Is your feature request related to a problem? Please describe.
There is no proper support for "strict" json schema mode in tool input schema due to not having 'additionalProperties' field.

Describe the solution you'd like
Support 'additionalProperties' in tool input schema same like in tool output schema.

Describe alternatives you've considered
Ignoring phpstan sealed array rule - makes code less reliable.

Additional context
This is sometimes needed when integrating mcp server with software that requires tool input/output schema to follow strict json schema (no additional properties allowed for example, all fields required etc). These sometimes refuse to work with tools whose schema isn't 'strict' enough.

まずツール入力スキーマの定義を見つけ、既存のツール出力スキーマにおける additionalProperties のサポートと比較します。結果として得られる入力スキーマが厳密な JSON Schema の要件を満たしていることを検証し、厳密なツールスキーマを受け入れる統合が期待どおりに動作することを確認します。