[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.

Beginne damit, die Definition des Schemas für Tool-Eingaben zu finden, und vergleiche sie mit der bestehenden Unterstützung des Tool-Ausgabeschemas für additionalProperties. Überprüfe das resultierende Eingabeschema anhand der Anforderungen des strikten JSON Schema und bestätige, dass Integrationen, die strikte Tool-Schemas akzeptieren, nun wie erwartet funktionieren.