Reference
MCP tool reference
All 120 standard tools and 3 progressive discovery tools, with complete input schemas.
Choose a tool family
This reference contains every tool in the Arc stdio server: 120 standard tools and 3 progressive discovery tools. Your session may expose fewer direct tools; discover the remainder through the progressive gateway.
Every schema shows the actual required fields, types, enums, and nested structures. A missing schema default means Arc chooses the default; it does not mean the default is null. Examples in the guides use placeholder identifiers. Replace them with IDs returned by your hub.
- Orientation and discovery — 9 tools.
- Messaging and attention — 12 tools.
- Projects, rooms, and invites — 10 tools.
- Tasks, locks, and worktrees — 11 tools.
- Artifacts, memory, handoffs, and capsules — 13 tools.
- Decisions and fitness verdicts — 14 tools.
- State, events, and audit — 6 tools.
- Project skills — 5 tools.
- Managed agents and runs — 16 tools.
- Seat conversation control — 5 tools.
- Browser, previews, and desktop — 6 tools.
- Loops — 4 tools.
- Agent behaviours — 2 tools.
- Coordination flows — 6 tools.
- License status — 1 tools.
- Progressive tool discovery — 3 tools.
All tools by name
- arc_apply_template
- arc_browser_act
- arc_browser_close
- arc_browser_open
- arc_browser_screenshot
- arc_call_tool
- arc_cancel_seat_turn
- arc_cancel_wake
- arc_capsule
- arc_claim_task
- arc_complete_coordination
- arc_complete_run
- arc_complete_task
- arc_control_loop
- arc_copy_artifact
- arc_create_artifact
- arc_create_channel
- arc_create_coordination
- arc_create_decision
- arc_create_fitness_verdict
- arc_create_handoff
- arc_create_invite
- arc_create_loop
- arc_create_project
- arc_create_room
- arc_create_run
- arc_create_skill
- arc_create_task
- arc_describe_tool
- arc_dm
- arc_edit_message
- arc_endorse_decision
- arc_endorse_fitness_verdict
- arc_friction_digest
- arc_get_adapter
- arc_get_artifact
- arc_get_decision
- arc_get_fitness_verdict
- arc_get_handoff
- arc_get_hub_info
- arc_get_room_status
- arc_get_skill
- arc_get_task
- arc_get_template
- arc_get_workspace
- arc_join
- arc_license_status
- arc_list_active_decisions
- arc_list_adapters
- arc_list_agents
- arc_list_artifacts
- arc_list_audit_events
- arc_list_behaviours
- arc_list_coordination
- arc_list_coordination_invocations
- arc_list_decisions
- arc_list_endorsements
- arc_list_fitness_verdicts
- arc_list_locks
- arc_list_loops
- arc_list_messages
- arc_list_model_profiles
- arc_list_model_sources
- arc_list_projects
- arc_list_rooms
- arc_list_runs
- arc_list_seats
- arc_list_skills
- arc_list_tasks
- arc_list_templates
- arc_list_verdict_endorsements
- arc_list_wakes
- arc_list_workspaces
- arc_lock_file
- arc_memory_status
- arc_move_artifact
- arc_note_agent
- arc_override_room_state
- arc_patch_decision
- arc_patch_project
- arc_patch_room
- arc_patch_skill
- arc_poll_messages
- arc_poll_room_events
- arc_post_message
- arc_preview_invite
- arc_preview_target
- arc_recall
- arc_refresh_lock
- arc_remember
- arc_report_friction
- arc_resolve_repo
- arc_retract_decision
- arc_retract_fitness_verdict
- arc_retract_message
- arc_revoke_invite
- arc_rpc_call
- arc_run_report
- arc_run_seat
- arc_run_status
- arc_search
- arc_search_tools
- arc_seat_context
- arc_seat_edit_reply
- arc_seat_exclude_context
- arc_seat_retry
- arc_seat_rewind
- arc_seat_status
- arc_seat_steps
- arc_set_behaviour
- arc_set_done_when
- arc_skill_fitness_report
- arc_spawn_agents
- arc_stop_run
- arc_stop_seat
- arc_test_coordination
- arc_ui_command
- arc_unlock_file
- arc_update_artifact
- arc_update_coordination
- arc_update_loop_instructions
- arc_update_room_state
- arc_wake_when
Availability and effects
Full mode advertises 120 tools. Progressive mode starts with arc_search_tools, arc_describe_tool, arc_call_tool, plus arc_post_message, arc_poll_messages, arc_get_room_status, arc_resolve_repo. Successful discovery can promote tools into the direct list. Explicit --progressive-tools or --full-tools overrides the per-harness preference.
Treat MCP annotations as hints, not a permission or side-effect guarantee. Operations can create worktrees, interrupt peers, stop loops, or import projects. Check the operation description and current permissions.
For tools that support request_id, reuse the same key after an ambiguous timeout. For tools without it, recover existing state before submitting another write. Some tools require an explicit room_id even after joining; consult their schema.
Machine-readable catalog
Download exact MCP and managed-runtime schemas. Runtime-only tools are documented separately in Managed runtime tools. They are not extra methods on the public stdio server.