deepseek-harness/docs/tool-catalog.md

Tool Schema Catalog

Every model-facing tool a shipped plugin contributes to ctx.tools: the name, description, and JSON-Schema parameters the model receives via the system-prompt assembly. It complements the cordis events & services catalogs (the wiring a plugin listens to and calls) and core-data-structures/ (the types those signatures move) — this page is the tools the agent is offered.

This file is GENERATED and verified fresh by pnpm run verify-tool-catalog (part of doc-sync) — do not edit it by hand. Unlike the cordis catalog (a pure source-AST pass), this generator BOOTS each tool plugin on a real context and reads ctx.tools.schemas(), because a tool schema is not statically knowable (runtime-spread enums, concatenated descriptions, config-driven names, raw-JSON-Schema MCP tools). A completeness guard globs packages/*/tool-* and fails if any package is missing from the generator's boot manifest, so a new tool cannot be silently undocumented. See the tool-schema-catalog RFC.

Scope: shipped product tools under packages/*/tool-*, each booted with its DEFAULT config. The registered tool NAME can be a load-time config (e.g. tool-subagent's toolName), so a deployment may surface a package under a different or additional name — a per-package note records those shipped aliases where they exist. The examples/ demo tools (e.g. echo) are excluded, matching the cordis catalog's packages-only scope.

Tool Package Map

This table connects model-visible tool names to the plugin package and service seams behind them. Exact JSON Schemas follow in the package sections below.

Tool package	Model-visible names	Requires	Writes / affects	Shipped aliases	Deployment note
@deepseek-ai/dsh-tool-ask-user	ask_user_question	ctx.tools, ctx.userInteraction	tool/call, tool/result after a UI/provider answers the question	-	ask_user_question pauses the tool call until the active UI provider returns a human answer.
@deepseek-ai/dsh-tools	run_code	ctx.tools, ctx.codeRuntime (execution time), ctx.systemPrompt	tool/call, one tool/code-dispatch per bridged sub-call, tool/result	-	Owned by the tool registry as a reserved transport outside filterable capability layers under mode: code / mode: both (see the Code Mode RFC). Under code it is the registry's only wire contribution; the other visible capabilities are declared in a generated TypeScript SDK section, and a program calls them through serialized bindings that re-enter the complete guarded tool pipeline and link each nested execution to this outer result.
@deepseek-ai/dsh-tool-bash	bash	ctx.tools, ctx.bash, ctx.tasks at call time for run_in_background	tool/call, tool/result	-	The bash tool is the model-facing consumer of the bash executor seam. A run_in_background run registers with the generic ctx.tasks runtime and is collected/stopped through the task_* tools from @deepseek-ai/dsh-tool-tasks; the enableRunInBackground config (default true) removes the parameter entirely when disabled.
@deepseek-ai/dsh-tool-cordis	cordis_inspect, cordis_mount, cordis_unmount	ctx.tools	tool/call, tool/result, live plugin-tree mutations (mount/unmount)	-	Ships in examples/cordis-agent only (a deliberate opt-in — mounted code gets the real ctx, see docs/rfc/implemented/feature/2026-07-08-self-referential-cordis-toolset.md). Plugins the model mounts may register ADDITIONAL model-visible tools at runtime; a full changed request header logs those tool-set changes.
@deepseek-ai/dsh-tool-fs	edit, read, write	ctx.tools, ctx.fs, ctx.systemPrompt	tool/call, fs/write-intent or fs/edit-intent for mutations, fs/observed after successful file operations, tool/result	-	The read-before-write/edit policy is added by @deepseek-ai/dsh-fs-policy (an fs/* event-gate plugin, no schema change); a deployment that loads these tools is expected to also load it. The tool schemas above are identical with or without the policy plugin.
@deepseek-ai/dsh-tool-fs-search	glob, grep	ctx.tools, ctx.bash, ctx.systemPrompt	tool/call, tool/result	-	glob and grep are bash-backed discovery tools: they run fixed ripgrep commands through ctx.bash as ordinary foreground calls (never background tasks). Capped results save the complete formatted list through the optional ctx.spillStore backend; returned locators are follow-up-readable/searchable when the backend exposes local paths in co-located deployments.
@deepseek-ai/dsh-tool-skill	skill	ctx.tools, ctx.skills	tool/call, tool/result	-	-
@deepseek-ai/dsh-tool-subagent	subagent	ctx.tools, ctx.subagents	tool/call, tool/result, child session events through the chosen provider	subagent, subagent_fork	The registered tool name is the load-time toolName config (default subagent); the schema above is that default. The shipped example agents load this package once per subagent backend, so the model additionally sees subagent_fork (bound to the fork backend) with an identical schema — see examples/repl-agent/cordis.yml and examples/acp-agent/cordis.yml.
@deepseek-ai/dsh-tool-tasks	task_kill, task_list, task_output	ctx.tools, ctx.tasks, ctx.systemPrompt	tool/call, tool/result, context/message via agent.inject() for background completion notices	-	The kind-agnostic background-task control surface: a background bash command and a background subagent are read, listed, and killed through the same three tools. Loading the plugin attaches the control surface that arms producers' ctx.tasks.start().
@deepseek-ai/dsh-tool-todo	todo_write	ctx.tools, owning Agent session	tool/call, todo/write, tool/result	-	todo_write is session-owned state; UIs render the latest todo/write event as a checklist or ACP plan.
@deepseek-ai/dsh-tool-workflow	workflow	ctx.tools, ctx.workflows, ctx.systemPrompt, a calling Agent (exec.agent parents the script children)	tool/call, tool/result	-	-
@deepseek-ai/dsh-tool-web	web_fetch, web_search	ctx.tools, ctx.web, ctx.systemPrompt	tool/call, tool/result	-	web_search and web_fetch keep provider selection behind ctx.web so model-visible schemas stay stable across backend swaps.

@deepseek-ai/dsh-tool-ask-user

ask_user_question

Ask the user a concise question when you need confirmation, a choice, or missing information before proceeding. Send one or more questions, each with a stable id that will be echoed in the answer.

{
  "type": "object",
  "properties": {
    "questions": {
      "type": "array",
      "description": "Questions to ask the user before continuing.",
      "items": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string",
            "description": "Stable id for this question; echoed in the answer."
          },
          "question": {
            "type": "string",
            "description": "The specific question to ask the user."
          },
          "header": {
            "type": "string",
            "description": "Optional short heading for the question, such as \"Confirm\" or \"Choose Mode\"."
          },
          "options": {
            "type": "array",
            "description": "Optional choices to show the user. If you recommend one, put it first and append \"(Recommended)\" to that label.",
            "items": {
              "type": "object",
              "properties": {
                "label": {
                  "type": "string",
                  "description": "Short user-facing option label."
                },
                "description": {
                  "type": "string",
                  "description": "One sentence explaining the tradeoff or impact."
                }
              },
              "required": [
                "label"
              ]
            }
          },
          "multi_select": {
            "type": "boolean",
            "description": "Whether the user may select more than one option. Defaults to false."
          }
        },
        "required": [
          "id",
          "question"
        ]
      }
    }
  },
  "required": [
    "questions"
  ]
}

Source: packages/ui/tool-ask-user/src/index.ts

ask_user_question pauses the tool call until the active UI provider returns a human answer.

@deepseek-ai/dsh-tools

run_code

Execute a TypeScript program against the available tools. Write the BODY of an async function (erasable syntax only; top-level await and return work) and call tools as await tools.name(args) per the declarations in the system prompt. Only what you print or return comes back — curate it.

{
  "type": "object",
  "properties": {
    "code": {
      "type": "string",
      "description": "The program: the body of an async TypeScript function."
    }
  },
  "required": [
    "code"
  ]
}

Source: packages/core/tools/src/code-mode.ts

Owned by the tool registry as a reserved transport outside filterable capability layers under mode: code / mode: both (see the Code Mode RFC). Under code it is the registry's only wire contribution; the other visible capabilities are declared in a generated TypeScript SDK section, and a program calls them through serialized bindings that re-enter the complete guarded tool pipeline and link each nested execution to this outer result.

@deepseek-ai/dsh-tool-bash

bash

Execute a bash command (bash -c) and return its stdout/stderr. Each call runs in a fresh shell: no state (cwd, variables, functions) persists between calls — pass workdir instead of using cd. Non-zero exits are reported as [exit code: N]. Current harness environment facts are exposed through managed $DSH_* variables; inspect them when needed. Commands may run under a file sandbox; a blocked file operation is reported as [sandbox: file access denied under <mode> mode] — a policy denial, not a bug in the command; do not retry another way. Long output is truncated to its tail; the full output is saved to a file whose path is reported when available. Set run_in_background: true for long-running commands: the call returns a task id immediately; read its output with task_output and stop it with task_kill.

{
  "type": "object",
  "properties": {
    "command": {
      "type": "string",
      "description": "The bash command to execute."
    },
    "description": {
      "type": "string",
      "description": "Clear, concise description of what this command does in active voice, 5-10 words (shown in the UI). Examples: \"ls\" → \"List files in current directory\"; \"git status\" → \"Show working tree status\"; \"npm install\" → \"Install package dependencies\"."
    },
    "timeoutMs": {
      "type": "number",
      "description": "Timeout in milliseconds. The executor applies its configured default and cap, and kills the command on expiry."
    },
    "workdir": {
      "type": "string",
      "description": "Working directory for this command. Defaults to the session workspace; a relative path is resolved against it."
    },
    "run_in_background": {
      "type": "boolean",
      "description": "Run in the background and return a task id immediately (collect with task_output, stop with task_kill). No timeout applies."
    }
  },
  "required": [
    "command",
    "description"
  ]
}

Source: packages/bash/tool-bash/src/index.ts

The bash tool is the model-facing consumer of the bash executor seam. A run_in_background run registers with the generic ctx.tasks runtime and is collected/stopped through the task_* tools from @deepseek-ai/dsh-tool-tasks; the enableRunInBackground config (default true) removes the parameter entirely when disabled.

@deepseek-ai/dsh-tool-cordis

cordis_inspect

Inspect the live cordis runtime that is running THIS agent. Read-only. Sections: services (every provided ctx service and the plugin fiber that owns it), plugins (a flat list of the loaded plugins with their lifecycle states), tools (the model-facing tools currently registered, i.e. what you can call), dynamic (plugins you mounted via cordis_mount: id, name, state, provided services, awaited services), api (method signatures AND argument/return type shapes for every LIVE service — read this before writing plugin code that calls a service), events (every harness event with its dispatch mode and exact signature — pick listener targets here). Omit what to get all six sections. With what:"api" or what:"events", pass an exact name to narrow to one service/event and include its original source JSDoc.

{
  "type": "object",
  "properties": {
    "what": {
      "type": "string",
      "description": "Limit the report to one section. Omit for all sections.",
      "enum": [
        "services",
        "plugins",
        "tools",
        "dynamic",
        "api",
        "events"
      ]
    },
    "name": {
      "type": "string",
      "description": "Exact service key or event name whose original JSDoc to include; valid only with what:\"api\" or what:\"events\"."
    }
  }
}

Source: packages/cordis/tool-cordis/src/index.ts

cordis_mount

Mount a NEW cordis plugin into the live runtime that is running THIS agent (self-modification). code runs as the body of an async JavaScript function in an isolated sandbox and MUST return a plugin. Two forms: FUNCTION form return (ctx) => { … } — declares no inject, so it can register tools, listen to events, and provide services, but reaching ANY service (e.g. ctx.bash) throws; use it only when you need no services. OBJECT form return { name?, inject: ['bash', 'llm', …], apply(ctx) { … } } — declares dependencies, and cordis activates the plugin only after the services exist; PREFER this form. You may reach ONLY the services you list in inject: an undeclared service throws even if it exists, because an undeclared dependency would not be cleaned up if its provider is unmounted. BEFORE calling a service from your code, read cordis_inspect what:"api" — it lists method signatures AND the type shapes of their arguments/returns (do not guess a field's type; e.g. a bash run's stdout is an object, not a string). Inside apply, use the standard cordis API: ctx.on(event, listener) to observe events (see cordis_inspect what:"events"), or call harness.registerTool(ctx, harness.defineTool({ name, description, parameters: { text: { type: 'string', required: true } }, async execute(args) { … } })) to give yourself a new tool — it becomes callable on your NEXT step. Tool parameters: each key IS a property — { type: 'string'|'number'|'boolean'|'object'|'array', required?: true, description?, enum?, items?, properties? }; a JSON-Schema-style { type: 'object', properties, required: […] } wrapper and type 'integer' are also accepted and normalized. A tool's execute MUST return an ARRAY of content blocks, e.g. return [{ type: 'text', text: someString }] — never a bare string. Mounts can COMPOSE: one plugin may ctx.provide('name', value) a service and another may declare inject: ['name'] to consume it — the consumer stays pending until the provider exists and returns to pending when the provider is unmounted. Everything registered inside apply is cleaned up automatically on unmount. Sandbox globals: console (tagged [cordis:<id>], writes through to the harness terminal), harness.defineTool, harness.registerTool, btoa, atob, TextEncoder, TextDecoder. Node APIs are DISABLED — do filesystem/network/timer work through the cordis services, never Node built-ins: require, setTimeout/setInterval, and fetch throw redirect errors; process and Buffer are undefined. Instead use inject: ['fs'] + ctx.fs for files, inject: ['web'] + ctx.web for HTTP, inject: ['bash'] + ctx.bash for processes, and inject: ['timer'] + ctx.setTimeout/ctx.setInterval for timing (fiber effects, auto-cleaned on unmount) — cordis_inspect what:"api" shows what THIS runtime provides. Write PLAIN JavaScript, not TypeScript (no as, no type annotations). Cautions: (1) waterfall events (e.g. tools/pre-execute) hand the listener a trailing next callback which MUST be called — returning without next() VETOES the call; prefer plain notification events unless you intend to intercept. (2) Never await something that only resolves after the current turn (your code runs INSIDE a tool call of that turn — it would deadlock). (3) Your ctx is a restricted façade: you can register tools, observe events, provide/consume services, and use timers, but framework internals (ctx.root, ctx.fiber, ctx.extend, ctx.plugin, …) are withheld. It is not a security boundary though — the services you inject (e.g. ctx.bash) reach the real runtime.

{
  "type": "object",
  "properties": {
    "code": {
      "type": "string",
      "description": "Body of an async JS function; must `return` the plugin to mount."
    }
  },
  "required": [
    "code"
  ]
}

Source: packages/cordis/tool-cordis/src/index.ts

cordis_unmount

Dispose a plugin previously mounted with cordis_mount, by id. All its registrations (event listeners, tools, services) are cleaned up through the cordis effect lifecycle. Returns only after disposal has fully completed (quiescence, not just a request to stop).

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "description": "The dynamic mount id returned by cordis_mount (e.g. \"dyn-1\")."
    }
  },
  "required": [
    "id"
  ]
}

Source: packages/cordis/tool-cordis/src/index.ts

Ships in examples/cordis-agent only (a deliberate opt-in — mounted code gets the real ctx, see docs/rfc/implemented/feature/2026-07-08-self-referential-cordis-toolset.md). Plugins the model mounts may register ADDITIONAL model-visible tools at runtime; a full changed request header logs those tool-set changes.

@deepseek-ai/dsh-tool-fs

edit

Edit an existing UTF-8 text file by replacing literal text.

{
  "type": "object",
  "properties": {
    "file_path": {
      "type": "string",
      "description": "Path to edit, resolved by the filesystem backend."
    },
    "old_string": {
      "type": "string",
      "description": "Literal text to replace. Must match exactly."
    },
    "new_string": {
      "type": "string",
      "description": "Literal replacement text. Use an empty string to delete the match."
    },
    "replace_all": {
      "type": "boolean",
      "description": "Replace all matches. Defaults to false; when false, old_string must appear exactly once."
    }
  },
  "required": [
    "file_path",
    "old_string",
    "new_string"
  ]
}

Source: packages/fs/tool-fs/src/index.ts

read

Read a UTF-8 text file and return line-numbered content.

{
  "type": "object",
  "properties": {
    "file_path": {
      "type": "string",
      "description": "Path to read, resolved by the filesystem backend."
    },
    "offset": {
      "type": "number",
      "description": "1-based first line to return. Defaults to 1."
    },
    "limit": {
      "type": "number",
      "description": "Maximum number of lines to return. Defaults to 2000."
    }
  },
  "required": [
    "file_path"
  ]
}

Source: packages/fs/tool-fs/src/index.ts

write

Create or fully replace a UTF-8 text file.

{
  "type": "object",
  "properties": {
    "file_path": {
      "type": "string",
      "description": "Path to write, resolved by the filesystem backend."
    },
    "content": {
      "type": "string",
      "description": "Full UTF-8 text content to write."
    }
  },
  "required": [
    "file_path",
    "content"
  ]
}

Source: packages/fs/tool-fs/src/index.ts

The read-before-write/edit policy is added by @deepseek-ai/dsh-fs-policy (an fs/* event-gate plugin, no schema change); a deployment that loads these tools is expected to also load it. The tool schemas above are identical with or without the policy plugin.

@deepseek-ai/dsh-tool-fs-search

glob

Find files whose paths match a glob pattern. Returns matching paths sorted by modification time, including hidden and ignored files (VCS metadata directories are excluded). Returns the first 100 paths inline; a capped result reports where the complete list was saved.

{
  "type": "object",
  "properties": {
    "pattern": {
      "type": "string",
      "description": "Glob pattern to match file paths against (e.g. \"**/*.ts\", \"src/**/*.test.js\")."
    },
    "path": {
      "type": "string",
      "description": "Directory to search in. Defaults to the session workspace; a relative path resolves against it."
    }
  },
  "required": [
    "pattern"
  ]
}

Source: packages/fs/tool-fs-search/src/index.ts

grep

Search file contents with a ripgrep regular expression. Returns matching lines with line numbers, grouped by file. Returns the first 250 matches inline; a capped result reports where the complete match list was saved. Use read on a matched file for surrounding context.

{
  "type": "object",
  "properties": {
    "pattern": {
      "type": "string",
      "description": "Regular expression to search for (ripgrep syntax)."
    },
    "path": {
      "type": "string",
      "description": "File or directory to search. Defaults to the session workspace; a relative path resolves against it."
    },
    "include": {
      "type": "string",
      "description": "One glob filter for which files to search (e.g. \"*.ts\", \"*.{js,jsx}\"). Not a list; negation is not supported."
    }
  },
  "required": [
    "pattern"
  ]
}

Source: packages/fs/tool-fs-search/src/index.ts

glob and grep are bash-backed discovery tools: they run fixed ripgrep commands through ctx.bash as ordinary foreground calls (never background tasks). Capped results save the complete formatted list through the optional ctx.spillStore backend; returned locators are follow-up-readable/searchable when the backend exposes local paths in co-located deployments.

@deepseek-ai/dsh-tool-skill

skill

Load the full instructions for an available skill. Call this with the exact skill name from the session skill catalog before acting on a task that names or clearly matches that skill.

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "description": "The exact skill name from the available skills list."
    }
  },
  "required": [
    "name"
  ]
}

Source: packages/skill/tool-skill/src/index.ts

@deepseek-ai/dsh-tool-subagent

subagent

Delegate a self-contained task to a subagent (a separate agent that works in its own context) and return its final result. Use this to offload focused, independent work — research, a scoped implementation, an analysis — so it does not consume this conversation's context. The subagent runs to completion and you receive only its final answer, not its intermediate steps. Give it a complete, standalone prompt: it does not see this conversation. Set run_in_background: true to return a task id; collect with task_output and stop with task_kill.

{
  "type": "object",
  "properties": {
    "description": {
      "type": "string",
      "description": "A short (3-5 word) description of the delegated task, for display."
    },
    "prompt": {
      "type": "string",
      "description": "The complete, self-contained task for the subagent. It does not share this conversation's context, so include everything it needs."
    },
    "run_in_background": {
      "type": "boolean",
      "description": "Run as a background task and return its id; collect with task_output or stop with task_kill."
    }
  },
  "required": [
    "description",
    "prompt"
  ]
}

Source: packages/subagent/tool-subagent/src/index.ts

The registered tool name is the load-time toolName config (default subagent); the schema above is that default. The shipped example agents load this package once per subagent backend, so the model additionally sees subagent_fork (bound to the fork backend) with an identical schema — see examples/repl-agent/cordis.yml and examples/acp-agent/cordis.yml.

@deepseek-ai/dsh-tool-tasks

task_kill

Request cancellation of a running background task by task id. Returns immediately; the task settles as killed once its work actually stops.

{
  "type": "object",
  "properties": {
    "task_id": {
      "type": "string",
      "description": "Task id returned by the tool that started the background work."
    },
    "reason": {
      "type": "string",
      "description": "Optional short reason, recorded in the log and forwarded to the task."
    }
  },
  "required": [
    "task_id"
  ]
}

Source: packages/tasks/tool-tasks/src/index.ts

task_list

List your background tasks (running and finished) with their ids, kinds, and statuses.

{
  "type": "object",
  "properties": {}
}

Source: packages/tasks/tool-tasks/src/index.ts

task_output

Read a background task. Stream tasks return only output since the previous read; final-output tasks return their result after settlement. Every response ends with [status: ...]. Reads are non-blocking unless wait: true, which waits up to the configured cap.

{
  "type": "object",
  "properties": {
    "task_id": {
      "type": "string",
      "description": "Task id returned by the tool that started the background work."
    },
    "wait": {
      "type": "boolean",
      "description": "Block until the task reaches a terminal status or the timeout expires. A timed-out wait returns [status: running] and leaves the task alive."
    },
    "timeout_ms": {
      "type": "number",
      "description": "Max wait in milliseconds (only meaningful with wait: true). Defaults to the configured wait timeout; capped by the configured maximum."
    }
  },
  "required": [
    "task_id"
  ]
}

Source: packages/tasks/tool-tasks/src/index.ts

The kind-agnostic background-task control surface: a background bash command and a background subagent are read, listed, and killed through the same three tools. Loading the plugin attaches the control surface that arms producers' ctx.tasks.start().

@deepseek-ai/dsh-tool-todo

todo_write

Record and update a structured task list for the current work. Send the ENTIRE list every call — it REPLACES the previous list (there are no partial updates, no per-item edits). Use it to plan multi-step work and show progress: add one todo per concrete step before you start. Keep AT MOST ONE todo in_progress at a time; while work remains, exactly one active task should be in_progress. Mark a todo completed the moment it is done (do not batch completions), and allow no in_progress item only once all work is complete. Skip the list for trivial single-step tasks. Statuses: pending (not started), in_progress (being worked on now), completed (finished).

{
  "type": "object",
  "properties": {
    "todos": {
      "type": "array",
      "description": "The COMPLETE task list, replacing any previous list.",
      "items": {
        "type": "object",
        "properties": {
          "content": {
            "type": "string",
            "description": "What the task is — a short imperative line."
          },
          "status": {
            "type": "string",
            "description": "pending (not started) | in_progress (now) | completed (done).",
            "enum": [
              "pending",
              "in_progress",
              "completed"
            ]
          }
        },
        "required": [
          "content",
          "status"
        ]
      }
    }
  },
  "required": [
    "todos"
  ]
}

Source: packages/todo/tool-todo/src/index.ts

todo_write is session-owned state; UIs render the latest todo/write event as a checklist or ACP plan.

@deepseek-ai/dsh-tool-workflow

workflow

Run a JavaScript workflow script that orchestrates subagents at scale. Use this for work that fans out across many independent pieces — an audit over many files, a migration, multi-angle research, adversarial verification of findings — where you write the orchestration as a script instead of delegating turn by turn.

The workflow's identity rides the meta parameter as JSON: required name (short kebab-case) and description strings, optional whenToUse string and phases array ({title, detail?, provider?, model?}). The script parameter is the plain JavaScript body ONLY (NOT TypeScript, and NO export const meta statement — meta is a parameter, not code), running with top-level await; end with return <value> — the value must be JSON-serializable and is this tool's result.

Script-body hooks:

• agent(prompt, opts?): Promise<any> — run one subagent to completion. Without opts.schema it resolves to the child's final text; with opts.schema (an object-rooted JSON Schema using ONLY type/properties/required/additionalProperties/items/enum/const — no oneOf/pattern/format/numeric bounds) it resolves to the validated object. Resolves null when the child fails (filter with .filter(Boolean)). Other opts: label (display), phase (progress group), and independent provider/model LLM target overrides (either may be provided alone). Anything else (effort/isolation/agentType) is rejected loudly.
• pipeline(items, ...stages): Promise<any[]> — run each item through the stages independently with NO barrier between stages (prefer this for multi-stage work). Each stage receives (prev, item, index). An ordinary stage throw drops that ITEM to null and skips its remaining stages.
• parallel(thunks): Promise<any[]> — run zero-argument functions concurrently and await ALL of them (a barrier; use only when a stage genuinely needs every prior result together). A throwing thunk resolves to null.
• phase(title) — start a progress phase; log(message) — narrate progress; args — the tool call's args input, verbatim.

Misused hooks (bad arguments, unknown options, unsupported schemas, tripped caps) throw errors that ALWAYS kill the script — they never dissolve into a per-item null.

Constraints: concurrency and total-agent caps apply; no filesystem, network, timers, or Node.js APIs are provided — the agents do the work, the script only coordinates them. The run executes in the foreground: this call returns when the whole script finishes.

{
  "type": "object",
  "properties": {
    "script": {
      "type": "string",
      "description": "The plain-JS workflow script body (top-level await allowed; NO `export const meta` statement; end with `return <json-value>`)."
    },
    "meta": {
      "type": "object",
      "description": "The workflow identity block (plain JSON — never code).",
      "properties": {
        "name": {
          "type": "string",
          "description": "Short kebab-case workflow name."
        },
        "description": {
          "type": "string",
          "description": "One-line description of what the workflow does."
        },
        "whenToUse": {
          "type": "string",
          "description": "Optional guidance on when this workflow applies."
        },
        "phases": {
          "type": "array",
          "description": "Optional phase declarations matched by phase() calls.",
          "items": {
            "type": "object",
            "properties": {
              "title": {
                "type": "string",
                "description": "The phase title phase() calls match by exact string."
              },
              "detail": {
                "type": "string",
                "description": "Optional one-line description of the phase."
              },
              "provider": {
                "type": "string",
                "description": "Optional provider override this phase is expected to use."
              },
              "model": {
                "type": "string",
                "description": "Optional model override this phase is expected to use."
              }
            },
            "required": [
              "title"
            ]
          }
        }
      },
      "required": [
        "name",
        "description"
      ]
    },
    "args": {
      "type": "object",
      "description": "Optional JSON input exposed to the script as the `args` global (wrap a bare list as a field, e.g. {\"files\": [...]})."
    }
  },
  "required": [
    "script",
    "meta"
  ]
}

Source: packages/workflow/tool-workflow/src/index.ts

@deepseek-ai/dsh-tool-web

web_fetch

Fetch the content of a specific HTTP(S) URL and return it decoded to text.

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "The HTTP(S) URL to fetch."
    }
  },
  "required": [
    "url"
  ]
}

Source: packages/web/tool-web/src/index.ts

web_search

Search the web for current information. Returns an optional summary answer and a list of source URLs.

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "description": "The search query."
    }
  },
  "required": [
    "query"
  ]
}

Source: packages/web/tool-web/src/index.ts

web_search and web_fetch keep provider selection behind ctx.web so model-visible schemas stay stable across backend swaps.