What it is
Plugin hooks can now react to tool-call dry-runs, config changes, and session attach/detach events.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.269.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
First cited
3The earliest release whose published evidence quoted tool.check was v2.1.269, 11 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table above.
Names beside it
Every settings key in the inventory starting tool, up to twelve of them.
tool.callTools a plugin registers reach the model through a local loopback MCP server. never mined
tool.outputA tool.output telemetry event can carry file contents, diffs and bash commands after a successful tool call, behind a gate. never mined
toolPolicyLegacy managed MCP server config fields now have a formal deprecation and rewrite system. never mined
toolResultRemedyTool results can now carry an internal 'remedy' value passed through to the assistant-visible message never mined
toolRulesPermission tool rules can now be redacted properly when exporting config. never mined
toolSearchEnabledTool search setting now also applies to Chat sessions, with version-based request shaping. never mined
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the settings key does. All settings keys.