Tool execution monitoring

How the agent loop REPL shows a running tool's progress and handles one that stalls - applies to every built-in tool, not just a specific category.

While a tool runs, the REPL shows a live monitor line - ⠴ bash_exec running (12m34s) · <latest output line> - refreshed every second, so a long command (a full test suite, a large download) is visibly alive instead of silent. The line is replaced by the usual ... done (elapsed) summary when the tool finishes.

Every tool gets a meaningful monitor line, not just bash_exec: the line is seeded with what the tool is acting on, derived from its arguments - the URL for web_scraper/http_request, the query for web_search/sql_query, the path for search_local, and so on (⠴ web_scraper running (3s) · https://example.com). Tools that stream output (like bash_exec) then replace the seed with their latest output line as it flows.

The same status line covers ! <cmd> / !! <cmd> shell commands and @file ref expansion: while a bang command is silent the line shows ⠴ ! make lint running (57s), and any real output erases the status line first so the two never collide.

The monitor also detects hung tools. Staleness is measured by silence, not wall-clock time - a long build that keeps printing never trips it. After 2 minutes without output the line warns (no output for 3m20s); after the stall timeout (default 10 minutes of silence, tune with /model tool set stall-timeout 5m, 0 disables) the tool is killed and the model receives a structured error explaining the hang so it can retry with a narrower or more verbose command, or run it in the background.

When a tool stalls, the default is auto-increase: the stall timeout is bumped by the increment (default 5m) and the bump is announced ([Auto-stall allocation: stall timeout increased by 5m. New timeout: 15m.]), so a long silent-but-alive command keeps running without a prompt. This is on by default.

Two other modes are available via /model tool set autokill <on|off> (autokill and auto-increase are mutually exclusive - enabling one disables the other):

autokill on - a stalled tool is killed at the stall timeout (no increase, no prompt), and the model gets a structured error so it can retry differently.
autokill off - the default auto-increase-and-announce behavior.

To be prompted interactively instead, turn both off in config; the REPL then offers (i)ncrease / (k)ill when a tool stalls.

Tools marked "cached" in Built-in Tools memoize successful results for the lifetime of the agent process: repeating the same query or URL returns the cached copy instantly instead of refetching. Failed and empty lookups are not cached, so they are retried on the next call. wolfram_alpha results are cached the same way.

Tool execution monitoring ​

See also ​

Tool execution monitoring

See also