> ## Documentation Index
> Fetch the complete documentation index at: https://docs.4minds.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Skills, Sub-Agents, and Tools

> SYMI has three related but distinct building blocks for getting work done: Tools, Skills, and Sub-Agents. This page explains what each one is for and how they fit together.

<Note>
  These terms get used loosely in conversation, but they mean different things architecturally. This page exists to keep them straight.
</Note>

## The short version

| | What it is | When it's used |
| - | - | - |
| **Tools** | An executable capability — reading or writing a file, querying a service, creating a document | Available to the model whenever the current session's configuration permits it |
| **Skills** | A packaged set of instructions for handling a particular kind of task or integration | Loaded on demand, only when SYMI determines the current task calls for it |
| **Sub-Agents** | A separately configured agent, scoped to a specific task, with its own instructions and model routing | Deployed for specialized or parallel work you've explicitly set up |

## Tools

Tools are the actual actions SYMI can take: reading and writing files, querying a connected service, creating a document, running code. What tools are available in a given session is determined by that session's configuration — not by anything in a prompt or a file. A workspace file can tell SYMI *how* to approach a task, but it can't grant SYMI a new tool it wasn't already given.

## Skills

Skills are specialized instructions for a particular kind of task — for example, how to properly build a spreadsheet, or how to work with a particular file format. Rather than loading every skill's full instructions into every conversation, SYMI keeps a lightweight catalog of what skills are available and what they're for, and only reads the full instructions for a skill when it's actually relevant to what you've asked.

This is why SYMI can draw on a large and growing library of specialized know-how without every single conversation carrying the weight of all of it.

<Tip>
  You don't need to invoke a skill by name. SYMI selects a relevant skill based on what you're asking it to do.
</Tip>

## Sub-Agents

Sub-agents are specialized agents you deploy within SYMI for a specific, ongoing purpose. Each sub-agent has:

* A **label** — a name identifying its purpose (e.g. "RFP Responder," "SOC Triage Agent")
* A **task prompt** — instructions defining what the sub-agent does and how it should behave
* A **model routing assignment** — which model the sub-agent queries

Sub-agents are the right place to define role-specific context — for example, *"You are a cybersecurity analyst working in a SOC. When given an alert, identify the affected system, classify the severity, and suggest a remediation step."* This is different from a Persona, which controls tone only, not role context.

**To create a sub-agent:**

1. Navigate to **Sub-Agents**.
2. Select **+ New Sub-Agent**.
3. Enter a label, a task prompt, and the model to route to.
4. Save and activate.

Sub-agents run with a narrower scope than your main conversation — they're built to focus on the task they're configured for, rather than carrying the full breadth of general capabilities.

## How they relate to the Scheduler

Scheduled (cron-style) jobs run as their own session type, distinct from your regular conversation. A scheduled job can invoke a sub-agent or a direct prompt on a recurring cadence, without needing an inbound trigger. See the [Scheduler section](/symi#scheduler) for configuring recurring jobs.

## Next steps

<CardGroup cols={2}>
  <Card title="Persistent Workspace" icon="folder" href="/symi/persistent-workspace">
    See how sub-agent and task output is stored.
  </Card>

  <Card title="Security & Isolation" icon="shield" href="/symi/security-and-isolation">
    Understand what governs tool access, regardless of what a prompt or skill requests.
  </Card>
</CardGroup>