Typed page-scoped tools reduce agent targeting errors compared to DOM actuation
DOM-driving agents must infer selectors and page state from pixels or markup, which is the dominant source of mis-targeted actions in browser-agent evaluations
A page-scoped tool registry binds the deliberation id server-side and validates arguments against a schema, structurally removing the cross-deliberation targeting mistake
The stdio MCP deployment of this same registry logged deliberationId confusion as its largest misuse class, and the curried WebMCP variant eliminated it in dogfood