opentax MCP Tools

• calculate_tax

  calculate tax

• calculate_business_tax

  calculate business tax

• calculate_fiduciary_tax

  calculate fiduciary tax

• determine_dependent

  determine dependent

• compute_state_return

  compute state return

• compute_return

  compute return

• verify_tax_claim

  verify tax claim

• list_input_facts Read-only

  list input facts

• explain_rule

  explain rule

• find_tax_cliffs Read-only

  find tax cliffs

• compare_filing_statuses

  compare filing statuses

• lookup_tax_parameter Read-only

  lookup tax parameter

• search_tax_rules Read-only

  search tax rules

• verify_fact

  verify fact

• is_tipped_occupation

  is tipped occupation

This list was read from the server itself, by connecting to it and calling tools/list on 24 September 2026. It is what the server actually exposes, not what its listing claims.

Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.