Function searchToolsWithKeywords

src/tools/ToolSearchTool/ToolSearchTool.ts:186–302

* Keyword-based search over tool names and descriptions. * Handles both MCP tools (mcp__server__action) and regular tools (CamelCase). * * The model typically queries with: * - Server names when it knows the integration (e.g., "slack", "github") * - Action words when looking for functionality (

(
  query: string,
  deferredTools: Tools,
  tools: Tools,
  maxResults: number,
)

 * - Tool-specific terms (e.g., "notebook", "shell", "kill")
 */
async function searchToolsWithKeywords(
  query: string,
  deferredTools: Tools,
  tools: Tools,
  maxResults: number,
): Promise<string[]> {
  const queryLower = query.toLowerCase().trim()

  // Fast path: if query matches a tool name exactly, return it directly.
  // Handles models using a bare tool name instead of select: prefix (seen
  // from subagents/post-compaction). Checks deferred first, then falls back
  // to the full tool set — selecting an already-loaded tool is a harmless
  // no-op that lets the model proceed without retry churn.
  const exactMatch =
    deferredTools.find(t => t.name.toLowerCase() === queryLower) ??
    tools.find(t => t.name.toLowerCase() === queryLower)
  if (exactMatch) {
    return [exactMatch.name]
  }

  // If query looks like an MCP tool prefix (mcp__server), find matching tools.
  // Handles models searching by server name with mcp__ prefix.
  if (queryLower.startsWith('mcp__') && queryLower.length > 5) {
    const prefixMatches = deferredTools
      .filter(t => t.name.toLowerCase().startsWith(queryLower))
      .slice(0, maxResults)
      .map(t => t.name)
    if (prefixMatches.length > 0) {
      return prefixMatches
    }
  }

  const queryTerms = queryLower.split(/\s+/).filter(term => term.length > 0)

  // Partition into required (+prefixed) and optional terms
  const requiredTerms: string[] = []
  const optionalTerms: string[] = []
  for (const term of queryTerms) {
    if (term.startsWith('+') && term.length > 1) {
      requiredTerms.push(term.slice(1))
    } else {
      optionalTerms.push(term)
    }
  }

  const allScoringTerms =
    requiredTerms.length > 0 ? [...requiredTerms, ...optionalTerms] : queryTerms
  const termPatterns = compileTermPatterns(allScoringTerms)

  // Pre-filter to tools matching ALL required terms in name or description
  let candidateTools = deferredTools
  if (requiredTerms.length > 0) {
    const matches = await Promise.all(
      deferredTools.map(async tool => {
        const parsed = parseToolName(tool.name)
        const description = await getToolDescriptionMemoized(tool.name, tools)
        const descNormalized = description.toLowerCase()
        const hintNormalized = tool.searchHint?.toLowerCase() ?? ''