> ## Documentation Index > Fetch the complete documentation index at: https://docs.braintrust.ti.trilogy.com/llms.txt > Use this file to discover all available pages before exploring further. # Expert Fields Reference > Complete reference for every field in Create/Edit Expert, with defaults and practical guidance. Use this page while creating or editing experts. It explains what each field controls, defaults, and how to choose values. ## Basics and Behavior | Field | Required | Default | What It Controls | Recommended Value | | ------------------------- | -------- | ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- | | **Name** | Yes | None | Display name in marketplace/cards | Clear role-based name, e.g. `Quarterly Planning Expert` | | **Description** | Yes | None | One-line summary in lists/details | 1-2 sentences focused on outcomes | | **Logo URL** | No | Empty | Avatar image shown in UI | Stable HTTPS image URL | | **About (Markdown)** | No | Empty | Long-form detail page content | Scope, examples, limits, expected outputs | | **System Prompt** | Yes | None | Core behavior/rules | Role, boundaries, tools, output format | | **Custom Hiring Message** | No | System message | First DM response after hire | One line with a suggested first question | | **Skills** | No | Empty | Reusable packaged behavior/files | Add only for structured reusable workflows | | **Categories** | No | Empty | Marketplace discoverability tags | 2-5 specific categories | | **Primary Model** | No | Claude Sonnet 4.6 | The AI model that powers this expert. Standard users can pick standard-tier models; admins can also pick premium models (e.g. Claude Opus 4.8, Claude Fable 5, or GPT-5.5). | Leave unset to use the platform default. Choose a lighter model for high-volume simple tasks; a heavier model for deep reasoning. | | **Reasoning effort** | No | Model-dependent | Per-expert override of the reasoning token budget. Enum string: one of `none`, `minimal`, `low`, `medium`, `high`, `xhigh`, `max`. Only honored by reasoning-capable models (currently Claude Sonnet 4.6, the Claude Opus family, Claude Fable 5, and the OpenAI GPT-5.4 / GPT-5.5 models); hidden for all other models (e.g. Claude Haiku 4.5 and the Gemini models). | Start with `medium`. See [Reasoning effort](/experts/creating-a-new-agent#reasoning-effort) for the full value guide. | ## Configuration ### Hives Hives are Braintrust's pre-built tool bundles. Always prefer hives over custom MCP servers when a hive exists for the service you need — they are tested, maintained, and handle per-user credential isolation automatically. See the [Hives Reference](/experts/hives-reference) for the full catalog. | Field | Required | Default | What It Controls | Recommended Value | | ---------------------- | -------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------ | | **Hives** | Usually | Empty | Built-in tool bundles that connect the expert to external services (Google Drive, Sheets, Notion, Jira, etc.) | Start minimal; add only what the expert actually needs | | **Hive Env Overrides** | No | Empty | Shared default values for a hive that apply to all users of this expert (e.g. a default Jira project key, a default database name) | Safe, non-sensitive shared defaults only — never credentials or API keys | ### MCP Servers Use custom MCP servers only when no built-in hive covers the service you need. You are responsible for maintaining the endpoint and debugging connection issues. | Field | Required | Default | What It Controls | Recommended Value | | --------------------- | ----------- | ------- | ------------------------------------------------------------ | ------------------------------------------------------------------------- | | **MCP Server Name** | If MCP used | None | Label for the server shown in the editor | Human-readable integration name | | **MCP Server URL** | If MCP used | None | The custom tool endpoint the expert connects to | Valid `https://` URL | | **MCP Transport** | If MCP used | `sse` | MCP protocol mode used to communicate with the server | Keep `sse` unless the server explicitly requires `streamable_http` | | **Verify MCP Server** | Recommended | Not run | Runs a connectivity and tool discovery check against the URL | Always run before saving — an unverified server fails silently at runtime | ## Automations (Advanced) | Field | Required | Default | What It Controls | Recommended Value | | --------------------------------- | -------- | -------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Automation Type** | Yes | `cron` when created as cron | Trigger mode | `cron` for schedules, `calendar` for event-driven | | **Display Name** | Yes | Empty | User-facing automation label | Action-focused and specific | | **Description** | No | Empty | Why/when automation is used | One sentence with clear use case | | **Execution Prompt** | Yes | Empty | Task instructions during trigger execution | Explicit action + output format | | **Policy Prompt** (calendar only) | No | Falls back to agent name + description | Tells the AI how to evaluate each calendar event — which to ignore, which to schedule, and how many minutes before the event to run | Write explicit criteria: which event types to act on, which to ignore, and your preferred lead time. See [Triggers](/automation/triggers) for examples. | ## Access and Visibility | Field | Required | Default | What It Controls | Recommended Value | | ------------------------------- | ------------ | --------- | ---------------------- | --------------------------------------------- | | **Expert Email (local part)** | Yes (create) | Empty | Unique expert identity | Lowercase, readable, stable (`sales-ops-bot`) | | **Visibility** | Yes | `Private` | Who can discover/hire | Start private, publish after validation | | **Access List** (Manage Access) | Depends | Empty | Who can edit/hire | Minimum required users/domains only | ## Edit-Only Fields | Field | Required | Default | What It Controls | Recommended Value | | ----------------------- | -------- | ------- | ---------------------------------------------------- | --------------------------------------------------------------------- | | **Images** | No | Empty | Visual examples on expert page | 2-4 screenshots of real outputs | | **Available On** | No | Empty | Platform compatibility hints | Only platforms you actively support | | **Google Drive Folder** | No | Empty | Synced knowledge source folder (RAG chunk injection) | See [Knowledge Base](/experts/knowledge-base) for how retrieval works | ## Common Mistakes and Fixes | Mistake | What Happens | Fix | | ---------------------------- | ---------------------------------------- | ------------------------------------------ | | Prompt is too generic | Low-quality/unstable responses | Add explicit role, scope, and output rules | | Too many hives initially | Noisy tool behavior and harder debugging | Start with minimal hives, expand later | | Broken/incorrect Logo URL | Missing avatar in UI | Use a public HTTPS image URL | | MCP URL saved without verify | Runtime tool failures | Verify each MCP server before saving | | Automation prompt too vague | Unusable scheduled output | Specify exact output shape and audience | | Access too broad | Unintended usage/edit risk | Restrict access list and roles | ## Validation Rules (Current Product Behavior) * **Name**: minimum 3 characters; letters/spaces only. * **Description**: minimum 10 characters. * **System Prompt**: minimum 10 characters. * **Email local part**: minimum 3; lowercase letters/numbers/`.`/`_`/`-`; no `@`. * **MCP server**: name and valid URL required. * **Automation template**: display name minimum 3; prompt minimum 10; names must be unique. ## System Prompt Patterns A well-structured system prompt is the single biggest factor in expert quality. Use these patterns as a starting point. ### Role Definition Start every prompt with a clear role statement: "You are \[ROLE] for \[CONTEXT]." This anchors the expert's behavior. ### Boundary Setting Explicitly state what the expert should **not** do. This prevents scope creep and hallucinated capabilities. ### Tool Usage Instructions Tell the expert when to use which tool. Without guidance, experts may use tools unnecessarily or miss tools they should use. ### Output Format Specification Define the expected format, length, and structure of responses. Be specific — "a bullet list" is better than "a summary." ### Uncertainty Handling Tell the expert what to do when it doesn't know: ask the user, state uncertainty, or skip the question. ### Template ``` You are [ROLE] for [CONTEXT]. **Your job:** [1-2 sentences on primary function] **What you do NOT do:** [3-5 explicit exclusions] **Tools available:** - [Tool name]: use when [condition] - [Tool name]: use when [condition] **Output format:** [specify format, length, structure] **When unsure:** [how to handle uncertainty - ask vs assume vs skip] ``` ## Recommended Configurations by Use Case ### Q\&A / Information Agent A simple expert that answers questions using a knowledge base. | Field | Recommended Value | | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Hives** | Minimal — Google Drive if using a knowledge base | | **System Prompt** | Strong, focused prompt with clear scope and refusal rules | | **Skills** | Domain knowledge skill if available | | **Triggers** | None — fully interactive | | **Drive Folder** | Connect a curated folder as a RAG knowledge source — see [Knowledge Base](/experts/knowledge-base) for how retrieval works and when to pair it with the Google Drive hive | ### Data Analysis Agent An expert that pulls data from various sources and produces analysis. | Field | Recommended Value | | ----------------- | ----------------------------------------------------------------------- | | **Hives** | Google Sheets, Supabase, NetSuite, or other data hives | | **System Prompt** | Include detailed output format instructions (tables, charts, summaries) | | **Skills** | Analysis templates or report format skills | | **Triggers** | Optional cron for recurring reports | ### Automated Reporting Agent An expert that runs on a schedule and delivers reports to a Space or DM. | Field | Recommended Value | | -------------------- | --------------------------------------------------------------- | | **Hives** | Data source hives (Sheets, NetSuite, Supabase) | | **System Prompt** | Focus on report structure, audience, and delivery format | | **Triggers** | Cron trigger with explicit execution prompt | | **Execution Prompt** | Specify exact data to pull, report format, and where to deliver | | **Delivery Mode** | Space for team reports, DM for individual summaries |