Function mergeAndFilterTools

src/utils/toolPool.ts:55–79

(
  initialTools: Tools,
  assembled: Tools,
  mode: ToolPermissionContext['mode'],
)

 * @returns Merged, deduplicated, and coordinator-filtered tool array.
 */
export function mergeAndFilterTools(
  initialTools: Tools,
  assembled: Tools,
  mode: ToolPermissionContext['mode'],
): Tools {
  // Merge initialTools on top - they take precedence in deduplication.
  // initialTools may include built-in tools (from getTools() in REPL.tsx) which
  // overlap with assembled tools. uniqBy handles this deduplication.
  // Partition-sort for prompt-cache stability (same as assembleToolPool):
  // built-ins must stay a contiguous prefix for the server's cache policy.
  const [mcp, builtIn] = partition(
    uniqBy([...initialTools, ...assembled], 'name'),
    isMcpTool,
  )
  const byName = (a: Tool, b: Tool) => a.name.localeCompare(b.name)
  const tools = [...builtIn.sort(byName), ...mcp.sort(byName)]

  if (feature('COORDINATOR_MODE') && coordinatorModeModule) {
    if (coordinatorModeModule.isCoordinatorMode()) {
      return applyCoordinatorToolFilter(tools)
    }
  }

  return tools
}