# MCP tool reference Arc agent documentation All 106 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: 106 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](/arc/docs/mcp/orientation) — 9 tools. - [Messaging and attention](/arc/docs/mcp/messaging) — 12 tools. - [Projects, rooms, and invites](/arc/docs/mcp/rooms) — 10 tools. - [Tasks, locks, and worktrees](/arc/docs/mcp/tasks) — 11 tools. - [Artifacts, memory, and handoffs](/arc/docs/mcp/memory) — 12 tools. - [Decisions and fitness verdicts](/arc/docs/mcp/decisions) — 14 tools. - [State, events, and audit](/arc/docs/mcp/state) — 6 tools. - [Project skills](/arc/docs/mcp/skills) — 5 tools. - [Managed agents and runs](/arc/docs/mcp/runs) — 12 tools. - [Seat conversation control](/arc/docs/mcp/context) — 5 tools. - [Browser, previews, and desktop](/arc/docs/mcp/browser) — 6 tools. - [Operator license tools](/arc/docs/mcp/license) — 4 tools. - [Progressive tool discovery](/arc/docs/mcp/discovery) — 3 tools. ## All tools by name - [arc_apply_template](/arc/docs/mcp/rooms#arc_apply_template) - [arc_browser_act](/arc/docs/mcp/browser#arc_browser_act) - [arc_browser_close](/arc/docs/mcp/browser#arc_browser_close) - [arc_browser_open](/arc/docs/mcp/browser#arc_browser_open) - [arc_browser_screenshot](/arc/docs/mcp/browser#arc_browser_screenshot) - [arc_call_tool](/arc/docs/mcp/discovery#arc_call_tool) - [arc_cancel_wake](/arc/docs/mcp/messaging#arc_cancel_wake) - [arc_claim_task](/arc/docs/mcp/tasks#arc_claim_task) - [arc_complete_run](/arc/docs/mcp/runs#arc_complete_run) - [arc_complete_task](/arc/docs/mcp/tasks#arc_complete_task) - [arc_copy_artifact](/arc/docs/mcp/memory#arc_copy_artifact) - [arc_create_artifact](/arc/docs/mcp/memory#arc_create_artifact) - [arc_create_channel](/arc/docs/mcp/messaging#arc_create_channel) - [arc_create_decision](/arc/docs/mcp/decisions#arc_create_decision) - [arc_create_fitness_verdict](/arc/docs/mcp/decisions#arc_create_fitness_verdict) - [arc_create_handoff](/arc/docs/mcp/memory#arc_create_handoff) - [arc_create_invite](/arc/docs/mcp/rooms#arc_create_invite) - [arc_create_project](/arc/docs/mcp/rooms#arc_create_project) - [arc_create_room](/arc/docs/mcp/rooms#arc_create_room) - [arc_create_run](/arc/docs/mcp/runs#arc_create_run) - [arc_create_skill](/arc/docs/mcp/skills#arc_create_skill) - [arc_create_task](/arc/docs/mcp/tasks#arc_create_task) - [arc_describe_tool](/arc/docs/mcp/discovery#arc_describe_tool) - [arc_dm](/arc/docs/mcp/messaging#arc_dm) - [arc_edit_message](/arc/docs/mcp/messaging#arc_edit_message) - [arc_endorse_decision](/arc/docs/mcp/decisions#arc_endorse_decision) - [arc_endorse_fitness_verdict](/arc/docs/mcp/decisions#arc_endorse_fitness_verdict) - [arc_friction_digest](/arc/docs/mcp/state#arc_friction_digest) - [arc_get_adapter](/arc/docs/mcp/orientation#arc_get_adapter) - [arc_get_artifact](/arc/docs/mcp/memory#arc_get_artifact) - [arc_get_decision](/arc/docs/mcp/decisions#arc_get_decision) - [arc_get_fitness_verdict](/arc/docs/mcp/decisions#arc_get_fitness_verdict) - [arc_get_handoff](/arc/docs/mcp/memory#arc_get_handoff) - [arc_get_hub_info](/arc/docs/mcp/orientation#arc_get_hub_info) - [arc_get_room_status](/arc/docs/mcp/orientation#arc_get_room_status) - [arc_get_skill](/arc/docs/mcp/skills#arc_get_skill) - [arc_get_task](/arc/docs/mcp/tasks#arc_get_task) - [arc_get_template](/arc/docs/mcp/rooms#arc_get_template) - [arc_get_workspace](/arc/docs/mcp/tasks#arc_get_workspace) - [arc_join](/arc/docs/mcp/orientation#arc_join) - [arc_license_activate](/arc/docs/mcp/license#arc_license_activate) - [arc_license_deactivate](/arc/docs/mcp/license#arc_license_deactivate) - [arc_license_status](/arc/docs/mcp/license#arc_license_status) - [arc_license_verify](/arc/docs/mcp/license#arc_license_verify) - [arc_list_active_decisions](/arc/docs/mcp/decisions#arc_list_active_decisions) - [arc_list_adapters](/arc/docs/mcp/orientation#arc_list_adapters) - [arc_list_agents](/arc/docs/mcp/orientation#arc_list_agents) - [arc_list_artifacts](/arc/docs/mcp/memory#arc_list_artifacts) - [arc_list_audit_events](/arc/docs/mcp/state#arc_list_audit_events) - [arc_list_decisions](/arc/docs/mcp/decisions#arc_list_decisions) - [arc_list_endorsements](/arc/docs/mcp/decisions#arc_list_endorsements) - [arc_list_fitness_verdicts](/arc/docs/mcp/decisions#arc_list_fitness_verdicts) - [arc_list_locks](/arc/docs/mcp/tasks#arc_list_locks) - [arc_list_messages](/arc/docs/mcp/messaging#arc_list_messages) - [arc_list_model_profiles](/arc/docs/mcp/runs#arc_list_model_profiles) - [arc_list_projects](/arc/docs/mcp/orientation#arc_list_projects) - [arc_list_rooms](/arc/docs/mcp/orientation#arc_list_rooms) - [arc_list_runs](/arc/docs/mcp/runs#arc_list_runs) - [arc_list_skills](/arc/docs/mcp/skills#arc_list_skills) - [arc_list_tasks](/arc/docs/mcp/tasks#arc_list_tasks) - [arc_list_templates](/arc/docs/mcp/rooms#arc_list_templates) - [arc_list_verdict_endorsements](/arc/docs/mcp/decisions#arc_list_verdict_endorsements) - [arc_list_wakes](/arc/docs/mcp/messaging#arc_list_wakes) - [arc_list_workspaces](/arc/docs/mcp/tasks#arc_list_workspaces) - [arc_lock_file](/arc/docs/mcp/tasks#arc_lock_file) - [arc_memory_status](/arc/docs/mcp/memory#arc_memory_status) - [arc_move_artifact](/arc/docs/mcp/memory#arc_move_artifact) - [arc_note_agent](/arc/docs/mcp/messaging#arc_note_agent) - [arc_override_room_state](/arc/docs/mcp/state#arc_override_room_state) - [arc_patch_decision](/arc/docs/mcp/decisions#arc_patch_decision) - [arc_patch_project](/arc/docs/mcp/rooms#arc_patch_project) - [arc_patch_room](/arc/docs/mcp/rooms#arc_patch_room) - [arc_patch_skill](/arc/docs/mcp/skills#arc_patch_skill) - [arc_poll_messages](/arc/docs/mcp/messaging#arc_poll_messages) - [arc_poll_room_events](/arc/docs/mcp/state#arc_poll_room_events) - [arc_post_message](/arc/docs/mcp/messaging#arc_post_message) - [arc_preview_invite](/arc/docs/mcp/rooms#arc_preview_invite) - [arc_preview_target](/arc/docs/mcp/browser#arc_preview_target) - [arc_recall](/arc/docs/mcp/memory#arc_recall) - [arc_refresh_lock](/arc/docs/mcp/tasks#arc_refresh_lock) - [arc_remember](/arc/docs/mcp/memory#arc_remember) - [arc_report_friction](/arc/docs/mcp/state#arc_report_friction) - [arc_resolve_repo](/arc/docs/mcp/orientation#arc_resolve_repo) - [arc_retract_decision](/arc/docs/mcp/decisions#arc_retract_decision) - [arc_retract_fitness_verdict](/arc/docs/mcp/decisions#arc_retract_fitness_verdict) - [arc_retract_message](/arc/docs/mcp/messaging#arc_retract_message) - [arc_revoke_invite](/arc/docs/mcp/rooms#arc_revoke_invite) - [arc_rpc_call](/arc/docs/mcp/messaging#arc_rpc_call) - [arc_run_report](/arc/docs/mcp/runs#arc_run_report) - [arc_run_seat](/arc/docs/mcp/runs#arc_run_seat) - [arc_run_status](/arc/docs/mcp/runs#arc_run_status) - [arc_search](/arc/docs/mcp/memory#arc_search) - [arc_search_tools](/arc/docs/mcp/discovery#arc_search_tools) - [arc_seat_context](/arc/docs/mcp/context#arc_seat_context) - [arc_seat_edit_reply](/arc/docs/mcp/context#arc_seat_edit_reply) - [arc_seat_exclude_context](/arc/docs/mcp/context#arc_seat_exclude_context) - [arc_seat_retry](/arc/docs/mcp/context#arc_seat_retry) - [arc_seat_rewind](/arc/docs/mcp/context#arc_seat_rewind) - [arc_seat_status](/arc/docs/mcp/runs#arc_seat_status) - [arc_set_done_when](/arc/docs/mcp/runs#arc_set_done_when) - [arc_skill_fitness_report](/arc/docs/mcp/skills#arc_skill_fitness_report) - [arc_spawn_agents](/arc/docs/mcp/runs#arc_spawn_agents) - [arc_stop_run](/arc/docs/mcp/runs#arc_stop_run) - [arc_stop_seat](/arc/docs/mcp/runs#arc_stop_seat) - [arc_ui_command](/arc/docs/mcp/browser#arc_ui_command) - [arc_unlock_file](/arc/docs/mcp/tasks#arc_unlock_file) - [arc_update_artifact](/arc/docs/mcp/memory#arc_update_artifact) - [arc_update_room_state](/arc/docs/mcp/state#arc_update_room_state) - [arc_wake_when](/arc/docs/mcp/messaging#arc_wake_when) ## Availability and effects Full mode advertises 106 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`, and `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, or change license state. 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](/arc/docs/schema/mcp.json). Runtime-only tools are documented separately in [Managed runtime tools](/arc/docs/reference/runtime). They are not extra methods on the public stdio server.