TrueNAS MCP

Create Dataset

create_dataset

Create a ZFS dataset in TrueNAS by specifying its full path, with a dry-run preview enabled by default to verify changes before creation.

Instructions

Create a ZFS dataset.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "name": "<name>"
    },
    "name": "create_dataset"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes	Full dataset path to create, e.g. "tank/data/apps".
`dry_run`	No	Preview only (default True); set False to create.

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 23, 2026

TDQS

C2.9/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full behavioral burden. It says only 'Create' and does not disclose mutation side effects, permissions, prerequisites, irreversibility, or the critical default dry-run behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no wasted words. It is efficiently structured, though its brevity leaves context to the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The input schema is fully described and an output schema exists, which reduces the description's burden. However, for a mutation tool with no annotations, the description is sparse about prerequisites, side effects, and the default preview-only behavior.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the schema fully documents both parameters, including the dry_run default and its effect. The description adds no parameter meaning beyond the schema, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Create a ZFS dataset.' It is clearly distinguishable from delete_dataset and list_datasets by the verb, but it does not explicitly name siblings or scope limits.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives no when-to-use guidance, no prerequisites, and no alternatives. Creating versus listing or deleting a dataset is implied by the verb, but the definition provides no explicit usage conditions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.