> ## Documentation Index > Fetch the complete documentation index at: https://www.truefoundry.com/llms.txt > Use this file to discover all available pages before exploring further. # Agent manifest reference > Complete AgentManifest field reference: model, skills, MCP servers, config, variables, and response format. For a guided walkthrough, see [Create an agent](/docs/agent-platform/agent-harness/sdk/create-agent). ## AgentManifest YAML spec The YAML below shows a complete agent spec. See [`AgentManifest`](#agentmanifest) for a description of every field. ```yaml lines theme={"dark"} type: truefoundry-agent name: support-bot description: A helpful support assistant model: name: anthropic/claude-sonnet-4-6 params: max_tokens: 4096 temperature: 1.0 reasoning_effort: low # Instructions are the system prompt for the agent. instructions: | You are a helpful support assistant that helps customers file issues. Current customer is {{customer_name}}. Their support tier is {{support_tier}}. # Seed messages sent after the system prompt but before `input`. messages: - role: user content: Hello. What can you help me with? # Variable definitions referenced in `messages` and `instructions`. variables: customer_name: default_value: "" description: "The name of the customer" support_tier: default_value: "" description: "The support tier of the customer" # Skills are mounted from the Skills Registry when the agent runs. skills: - fqn: agent-skill:truefoundry/skills/web-search:1 preload: true - fqn: agent-skill:truefoundry/skills/code-interpreter:2 preload: false mcp_servers: - name: zendesk preload: false enable_tools: ["@read-only", "delete_ticket"] disable_tools: ["get_users", "list_users"] preload_tools: ["list_tickets"] require_approval_for_tools: ["@write", "@destructive", "delete_ticket"] response_format: type: text config: iteration_limit: 25 timeout_seconds: 900 sandbox: enabled: true file_downloads: true dynamic_sub_agents: enabled: true context_management: compaction: enabled: true compaction_threshold_tokens: 60000 large_tool_response: enabled: true individual_tool_response_token_threshold: 4000 total_tool_response_token_threshold: 8000 preview_number_of_characters: 500 generative_ui: enabled: false ask_user_questions: enabled: true collaborators: [] ``` ## Reference ### AgentManifest `AgentManifest` is the shape of the spec saved in the Agent Registry. It shares all [agent configuration fields](#agent-configuration) below. Note that `variables` is a map of objects with `default_value` and `description`, not plain string values. Callers can override these with plain string values at invocation time when running the agent. | Field | Type | Required | Description | | ----------------- | -------------------------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `type` | `"truefoundry-agent"` | Yes | Manifest type discriminator. | | `name` | string | Yes | Unique identifier for the agent. 3 to 32 lowercase alphanumeric characters; may contain `-` in between; cannot start with a number. | | `description` | string | Yes | Human-readable description of what the agent does. Max 2000 characters. | | `tags` | `map` | No | Key-value tags for the agent. Keys and values are up to 100 characters. | | `model` | object | Yes | LLM to use. See [`model`](#model). | | `skills` | array | No | See [`skills[]`](#skills). | | `mcp_servers` | array | No | See [`mcp_servers[]`](#mcp_servers). | | `instructions` | string | No | System prompt. Supports `{{variable}}` placeholders resolved from `variables` at runtime. | | `messages` | array | No | Seed messages. See [`messages[]`](#messages). | | `variables` | `map` | No | Variable definitions. Each entry has optional `default_value` (string) and `description` (string). Callers override with plain string values at invocation time. | | `sample_inputs` | array | No | Example inputs shown on the Agent Chat page. See [`sample_inputs[]`](#sample_inputs). | | `response_format` | object | No | See [`response_format`](#response_format). | | `config` | object | No | See [`config`](#config). | | `collaborators` | array | Yes | Users who have access to this agent. | *** ### Agent configuration The fields below make up the agent configuration shared by the [`AgentManifest`](#agentmanifest). #### `model` | Field | Type | Required | Description | | -------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------ | | `name` | string | Yes | Model identifier in `provider/model-name` format (e.g. `openai-main/gpt-4o`, `anthropic/claude-sonnet-4-6`). | | `params` | object | No | Model parameters. See [`model.params`](#modelparams). | #### `model.params` Known parameters are listed below. Any additional provider-specific keys are also accepted. | Field | Type | Required | Description | | --------------------- | ------- | -------- | ---------------------------------------------------------------------------------- | | `max_tokens` | integer | No | Maximum number of tokens to generate. | | `reasoning_effort` | string | No | Reasoning depth when supported. One of `none`, `minimal`, `low`, `medium`, `high`. | | `temperature` | float | No | Sampling temperature (0-2). Higher values increase randomness. | | `top_p` | float | No | Nucleus sampling threshold (0-1). Alternative to `temperature`. | | `top_k` | integer | No | Top-K sampling when supported by the provider. | | `parallel_tool_calls` | boolean | No | Allow the model to request multiple tool calls in parallel when supported. | *** #### `messages[]` Seed messages injected after the system prompt and before the user's `input`. Only user messages are supported. | Field | Type | Required | Description | | --------- | -------- | -------- | --------------------------------------------------------------------------------------- | | `role` | `"user"` | Yes | Only `user` messages are supported. | | `content` | string | Yes | Text content of the message (non-empty). Supports `{{variable}}` template placeholders. | *** #### `skills[]` Each entry mounts an agent skill from the Skills Registry. | Field | Type | Required | Description | | --------- | ------- | -------- | -------------------------------------------------------------------------------------------- | | `fqn` | string | Yes | Fully qualified name of the agent skill, e.g. `agent-skill:truefoundry/skills/web-search:1`. | | `preload` | boolean | No | If `true`, the `SKILL.md` content is injected into the agent context. Defaults to `false`. | *** #### `mcp_servers[]` Each entry configures an MCP server whose tools are made available to the agent. Tool selectors support special tags that use [MCP tool annotations](https://modelcontextprotocol.io/specification/2025-11-25/schema#toolannotations): | Tag | Matches | | -------------- | ------------------------------------------------------------------------------------------------------------------------------- | | `@all` | Every tool exposed by the server. | | `@read-only` | Tools with `readOnlyHint: true` explicitly set. | | `@destructive` | Tools with `destructiveHint: true` explicitly set (implies `readOnlyHint: false`). | | `@write` | Tools that do **not** have `readOnlyHint: true` - including all `@destructive` tools. `@write` is a superset of `@destructive`. | Tags and explicit tool names can be combined in the same list. | Field | Type | Required | Description | | ---------------------------- | ---------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `name` | string | Yes | Name of the MCP server as registered in the platform. | | `preload` | boolean | No | When `true` (default), this server's tools are preloaded into context. When `false`, tools are discovered lazily and only `preload_tools` stay eager. Defaults to `true`. | | `enable_tools` | array of strings | No | Allowlist of tools (or tags) to expose to the agent. Defaults to `["@all"]`. | | `disable_tools` | array of strings | No | Blocklist of tools (or tags) to hide from the agent even if matched by `enable_tools`. Defaults to `[]`. | | `preload_tools` | array of strings | No | When `preload` is `false`, tools to still preload into context. Defaults to `[]`. | | `require_approval_for_tools` | array of strings | No | Tools (or tags) that require explicit human approval before the agent can call them. Defaults to `["@write", "@destructive"]`. | *** #### `sample_inputs[]` Example inputs shown on the Agent Chat page (via "Try Now" on the agent listing). Each entry has: | Field | Type | Required | Description | | ----------- | --------------------- | -------- | -------------------------------------------------------------- | | `text` | string | No | Example input text for the agent. | | `variables` | `map` | No | Variable values for the prompt variables defined on the agent. | *** #### `response_format` | Field | Type | Required | Description | | ------------- | ------ | -------- | --------------------------------------------------------------------------------------------------------------------------------------- | | `type` | string | Yes | Output format for the final response. One of `text`, `json_object`, or `json_schema`. | | `json_schema` | object | No | Required when `type` is `json_schema`. Has `name` (string), optional `description`, optional `schema`, and optional `strict` (boolean). | *** #### `config` | Field | Type | Required | Description | | -------------------- | ------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | `iteration_limit` | integer | No | Maximum number of reasoning iterations (tool call + model response cycles) a turn may perform before it is forced to stop. Between 1 and 1024. | | `timeout_seconds` | integer | No | Maximum wall-clock time in seconds a turn is allowed to run before it is forcibly terminated. | | `sandbox` | object | No | Sandboxed code execution settings. See [`config.sandbox`](#configsandbox). | | `dynamic_sub_agents` | object | No | Controls whether the agent can spawn sub-agents dynamically. See [`config.dynamic_sub_agents`](#configdynamic_sub_agents). | | `context_management` | object | No | Controls how the agent manages its context window. See [`config.context_management`](#configcontext_management). | | `generative_ui` | object | No | Controls whether the agent can emit generative UI components. See [`config.generative_ui`](#configgenerative_ui). | | `ask_user_questions` | object | No | Controls whether the agent can pause to ask the user clarifying questions. See [`config.ask_user_questions`](#configask_user_questions). | #### `config.sandbox` | Field | Type | Required | Description | | ---------------- | ------- | -------- | --------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Enable an isolated sandbox environment for code execution. Defaults to `false`. | | `file_downloads` | boolean | No | Allow files generated inside the sandbox to be downloaded by the caller. Defaults to `false`. | #### `config.dynamic_sub_agents` | Field | Type | Required | Description | | --------- | ------- | -------- | --------------------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Allow the agent to spawn sub-agents dynamically to parallelize or delegate subtasks. Defaults to `false`. | #### `config.context_management` | Field | Type | Required | Description | | --------------------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `compaction` | object | No | Automatic context compaction settings. See [`config.context_management.compaction`](#configcontext_managementcompaction). | | `large_tool_response` | object | No | Settings for handling tool responses that exceed token limits. See [`config.context_management.large_tool_response`](#configcontext_managementlarge_tool_response). | #### `config.context_management.compaction` | Field | Type | Required | Description | | ----------------------------- | ------- | -------- | ----------------------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Enable automatic compaction of conversation history when approaching the context limit. Defaults to `true`. | | `compaction_threshold_tokens` | integer | No | Token count at which compaction is triggered. | #### `config.context_management.large_tool_response` | Field | Type | Required | Description | | ------------------------------------------ | ------- | -------- | -------------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Enable truncation of tool responses that exceed token thresholds. Defaults to `true`. | | `individual_tool_response_token_threshold` | integer | No | Token limit for a single tool response before it is truncated. | | `total_tool_response_token_threshold` | integer | No | Combined token limit across all tool responses in a single iteration before truncation is applied. | | `preview_number_of_characters` | integer | No | Number of characters to retain as a preview when a tool response is truncated. | #### `config.generative_ui` | Field | Type | Required | Description | | --------- | ------- | -------- | ------------------------------------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Allow the agent to emit structured UI components (e.g. cards, forms) as part of its response stream. Defaults to `false`. | #### `config.ask_user_questions` | Field | Type | Required | Description | | --------- | ------- | -------- | --------------------------------------------------------------------------------------------------------------- | | `enabled` | boolean | No | Allow the agent to pause mid-run and ask the user a clarifying question before continuing. Defaults to `false`. |