DeepSeek Harness: 最初のツール開発：defineTool

import { defineTool } from '@deepseek-ai/dsh'

export default defineTool({
  name: 'tool_name',
  description: 'このツールが何をするか',
  parameters: {
    type: 'object',
    properties: { /* ... */ },
    required: [ /* ... */ ]
  },
  async execute(params, ctx) {
    // ツールロジック
    return result
  }
})

// 方法1：デフォルトエクスポート
export default defineTool({ ... })

// 方法2：名前付きエクスポート
export const myTool = defineTool({ ... })

name: 'file_count'        // ✅
name: 'fileCount'         // ❌ 非推奨
name: 'FileCount'         // ❌ 非推奨
name: 'file-count'        // ❌ 非推奨

// ❌ 悪い説明
description: 'テスト用のツール'

// ✅ 良い説明
description: 'Count the number of files in a directory. Returns total count and breakdown by file extension. Use when user asks about file statistics or directory contents.'

parameters: {
  type: 'object',
  properties: {
    param_name: {
      type: 'string',
      description: 'パラメータの説明'
    }
  },
  required: ['param_name']
}

properties: {
  path: {
    type: 'string',
    description: 'ファイル数をカウントするディレクトリパス'
  },
  pattern: {
    type: 'string',
    description: 'ファイルをフィルタリングする Glob パターン（例：*.ts）',
    default: '*'
  }
}

properties: {
  sort_by: {
    type: 'string',
    enum: ['name', 'size', 'date'],
    description: 'ソート基準'
  }
}

properties: {
  extensions: {
    type: 'array',
    items: { type: 'string' },
    description: '含めるファイル拡張子（例：[".ts", ".js"]）'
  }
}

properties: {
  options: {
    type: 'object',
    properties: {
      recursive: { type: 'boolean', default: false },
      includeHidden: { type: 'boolean', default: false }
    }
  }
}

required: ['path']          // path は必須
// pattern にはデフォルトがあるため必須ではない

async execute(params: Params, ctx: Context): Promise<Result>

async execute({ path }, ctx) {
  const count = await countFiles(path)
  return { count, path }
}

export const inject = ['fs']

export default defineTool({
  name: 'file_count',
  // ...
  async execute({ path }, ctx) {
    const files = await ctx.fs.readdir(path)
    return { count: files.length }
  }
})

async execute({ path }, ctx) {
  try {
    const files = await ctx.fs.readdir(path)
    return { count: files.length, path }
  } catch (error) {
    return {
      error: true,
      message: `Failed to read directory: ${error.message}`
    }
  }
}

// ✅ 構造化返却
return {
  count: 42,
  path: '/home/alice/project',
  breakdown: {
    typescript: 28,
    javascript: 10,
    other: 4
  }
}

// ❌ プレーンテキスト返却
return 'Found 42 files in /home/alice/project'

import { Context } from '@deepseek-ai/cordis'
import { defineTool } from '@deepseek-ai/dsh'

const fileCountTool = defineTool({
  name: 'file_count',
  description: 'Count files in a directory',
  parameters: {
    type: 'object',
    properties: {
      path: { type: 'string', description: 'Directory path' }
    },
    required: ['path']
  },
  async execute({ path }, ctx) {
    const files = await ctx.fs.readdir(path)
    return { count: files.length }
  }
})

export const name = 'tool-file-count'
export const inject = ['tools', 'fs']

export function apply(ctx: Context) {
  ctx.tools.register(fileCountTool)
}

export function apply(ctx: Context) {
  ctx.tools.register(fileCountTool)
  ctx.tools.register(fileSizeTool)
  ctx.tools.register(fileSearchTool)
}

export function apply(ctx: Context) {
  const tools = [fileCountTool, fileSizeTool]
  
  for (const tool of tools) {
    ctx.tools.register(tool)
    ctx.logger.info(`registered tool: ${tool.name}`)
  }
}

┌─────────────────────────────────────┐
│ 🔧 Tools                            │
├─────────────────────────────────────┤
│ file_count  │ Count files in a dir  │
│ file_size   │ Get file size info    │
│ file_search │ Search for files      │
└─────────────────────────────────────┘

🤖 Agent：
🔧 Using tool：file_count
  → path：/home/alice/project
  
  Result：{ count：42, path："//home/alice/project" }

import { Context } from '@deepseek-ai/cordis'
import { defineTool } from '@deepseek-ai/dsh'

export const name = 'tool-file-count'
export const inject = ['tools', 'fs']

const fileCountTool = defineTool({
  name: 'file_count',
  description: 'Count the number of files in a directory. Returns total count and breakdown by file extension. Use when user asks about file statistics or directory contents.',
  parameters: {
    type: 'object',
    properties: {
      path: {
        type: 'string',
        description: 'Absolute or relative path to the directory'
      },
      recursive: {
        type: 'boolean',
        description: 'Whether to count files in subdirectories',
        default: false
      },
      extensions: {
        type: 'array',
        items: { type: 'string' },
        description: 'Filter by file extensions (e.g. [".ts", ".js"]). Count all if omitted.'
      }
    },
    required: ['path']
  },
  async execute({ path, recursive, extensions }, ctx) {
    try {
      const entries = recursive
        ? await ctx.fs.readdirRecursive(path)
        : await ctx.fs.readdir(path)

      let files = entries.filter(e => !e.isDirectory)

      if (extensions && extensions.length > 0) {
        files = files.filter(f =>
          extensions.some(ext => f.name.endsWith(ext))
        )
      }

      const breakdown: Record<string, number> = {}
      for (const f of files) {
        const ext = f.name.includes('.')
          ? '.' + f.name.split('.').pop()
          : '(no extension)'
        breakdown[ext] = (breakdown[ext] || 0) + 1
      }

      return {
        count: files.length,
        path,
        recursive,
        breakdown
      }
    } catch (error: any) {
      return {
        error: true,
        message: `Failed to count files: ${error.message}`
      }
    }
  }
})

export function apply(ctx: Context) {
  ctx.tools.register(fileCountTool)
  ctx.logger.info('file_count tool registered')
}

# cordis.yml に登録
pnpm dsh web --patch

# Web UI でテスト
# 👤 Alice：/home/alice/project ディレクトリにファイルはいくつありますか？
# 🤖 Agent：🔧 file_count → { count：42, breakdown：{ ".ts"：28, ".js"：10, ".json"：4 } }