context_builder

System catalog id for discovery and primitives. Live tool schemas are built in internal/runtime/context/injection/builtin.go (plus catalog). The package dir internal/modules/context_builder is a stub.

Always / mode-dependent builtins

From builtinToolSpecs() (injection depends on tool_injection mode):

Tool	Role
search_tools	Three modes: query (hybrid search), category (list tools in a domain, paginated), no args (list domains). Replaces old list_categories / browse_category tools.
get_tool	Full schema for one tool
execute_tool	Run a tool by name + params object
run_parallel	Concurrent calls via tasks: [{tool, args}, ...] (legacy actions/name/params also accepted)
background_run	Launch / status / wait / cancel / list; also notify_when, wait_for, watch loops, signal, stdin

Conditionally injected

Tool	When
ask_user	Ask-user enabled for the app/agent
call_app	Call-app enabled
use_skill	Skills enabled
Memory tools	Memory enabled
agent + kv	Agent spawn enabled (AgentToolSpec)

kv modes

kv(key, value?), kv(key, delete=true), kv(list=true).

Not separate tools

• No list_categories / browse_category catalog tools
• No watch_start family; use background_run(watch=true, ...)
• No cron_native schedule tools; use scheduler

Related

• Built-in tools
• Primitives
• Tools / injection