deepseek-ai/deepseek-harness · error · Error

tool provider returned reserved tool name "${TOOL_ORDER_REST

Error message

tool provider returned reserved tool name "${TOOL_ORDER_REST}" (reserved for toolOrder's rest entry)

What it means

Error "tool provider returned reserved tool name "${TOOL_ORDER_REST}" (reserved for toolOrder's rest entry)" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/core/system-prompt/src/index.ts:167

  for (const name of toolOrder) {
    if (seen.has(name)) throw new Error(`toolOrder lists "${name}" more than once`)
    seen.add(name)
  }
  if (!seen.has(TOOL_ORDER_REST)) {
    throw new Error(`toolOrder must contain the "${TOOL_ORDER_REST}" rest entry (where unlisted tools are inserted)`)
  }
  return toolOrder
}

/**
 * Apply configured tool order, inserting unlisted tools lexicographically at
 * {@link TOOL_ORDER_REST}. Unknown configured names fail; known but restricted
 * names may be absent.
 */
function orderTools(tools: ToolSchema[], toolOrder: string[] | undefined, knownNames: ReadonlySet<string>): ToolSchema[] {
  const reserved = tools.find(tool => tool.name === TOOL_ORDER_REST)
  if (reserved !== undefined) {
    throw new Error(`tool provider returned reserved tool name "${TOOL_ORDER_REST}" (reserved for toolOrder's rest entry)`)
  }
  if (toolOrder === undefined) return tools.sort(compareToolNames)
  const unknown = toolOrder.filter(name => name !== TOOL_ORDER_REST && !knownNames.has(name))
  if (unknown.length > 0) {
    throw new Error(`toolOrder lists unregistered tool${unknown.length > 1 ? 's' : ''} ${unknown.map(name => `"${name}"`).join(', ')}; known tools: ${[...knownNames].sort().join(', ') || '(none)'}`)
  }
  const listed = new Set(toolOrder)
  const rest = tools.filter(tool => !listed.has(tool.name)).sort(compareToolNames)
  return toolOrder.flatMap(name =>
    name === TOOL_ORDER_REST ? rest : tools.filter(tool => tool.name === name))
}

/** Lexicographic (code-unit) name comparison — locale-independent, so the order is identical on every machine. */
function compareToolNames(a: ToolSchema, b: ToolSchema): number {
  return a.name < b.name ? -1 : a.name > b.name ? 1 : 0
}

/** Plugin config: the deployment-authored fragment of the system prompt (see {@link Config.persona} for its contract). */

View on GitHub (pinned to b150a551b8)

When it happens

Trigger: Thrown at packages/core/system-prompt/src/index.ts:167 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/a88ee407e0062cff. Report an issue: GitHub.