Function validateInput

src/tools/SkillTool/SkillTool.ts:354–430

({ skill }, context)

  toAutoClassifierInput: ({ skill }) => skill ?? '',

  async validateInput({ skill }, context): Promise<ValidationResult> {
    // Skills are just skill names, no arguments
    const trimmed = skill.trim()
    if (!trimmed) {
      return {
        result: false,
        message: `Invalid skill format: ${skill}`,
        errorCode: 1,
      }
    }

    // Remove leading slash if present (for compatibility)
    const hasLeadingSlash = trimmed.startsWith('/')
    if (hasLeadingSlash) {
      logEvent('tengu_skill_tool_slash_prefix', {})
    }
    const normalizedCommandName = hasLeadingSlash
      ? trimmed.substring(1)
      : trimmed

    // Remote canonical skill handling (ant-only experimental). Intercept
    // `_canonical_<slug>` names before local command lookup since remote
    // skills are not in the local command registry.
    if (
      feature('EXPERIMENTAL_SKILL_SEARCH') &&
      process.env.USER_TYPE === 'ant'
    ) {
      const slug = remoteSkillModules!.stripCanonicalPrefix(
        normalizedCommandName,
      )
      if (slug !== null) {
        const meta = remoteSkillModules!.getDiscoveredRemoteSkill(slug)
        if (!meta) {
          return {
            result: false,
            message: `Remote skill ${slug} was not discovered in this session. Use DiscoverSkills to find remote skills first.`,
            errorCode: 6,
          }
        }
        // Discovered remote skill — valid. Loading happens in call().
        return { result: true }
      }
    }

    // Get available commands (including MCP skills)
    const commands = await getAllCommands(context)

    // Check if command exists
    const foundCommand = findCommand(normalizedCommandName, commands)
    if (!foundCommand) {
      return {
        result: false,
        message: `Unknown skill: ${normalizedCommandName}`,
        errorCode: 2,
      }
    }

    // Check if command has model invocation disabled