TrueNAS MCP

List Snapshots

list_snapshots

Retrieve ZFS snapshots, optionally filtered by dataset, to inspect available restore points and backup state.

Instructions

List ZFS snapshots.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

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

Input Schema

Name	Required	Description	Default
`dataset`	No	Restrict to snapshots of one dataset, e.g. tank/data (optional).

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?

With no annotations provided, the description carries the full burden of behavioral disclosure and adds essentially nothing: no statement that it is read-only (implied only by 'List'), no note on whether results span all datasets or are paginated, and no indication of how the optional dataset filter behaves when omitted.

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?

A single front-loaded sentence with zero waste. It is efficient, though the terseness edges toward under-specification given the total absence of annotations.

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

Completeness2/5

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

For a tool with no annotations and no stated usage context, the description is too thin: it omits whether listing is scoped by default, and provides no safety or filtering context beyond the schema. The presence of an output schema does relieve it of explaining return values.

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 single optional 'dataset' parameter is well documented in the schema with an example. The description contributes no additional parameter meaning, 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?

States a specific verb and resource ('List ZFS snapshots'), which is unambiguous about the operation. However, it makes no attempt to differentiate itself from siblings like create_snapshot, delete_snapshot, or list_datasets, which an agent must disambiguate on its own.

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?

There is no guidance on when to use this versus create_snapshot/delete_snapshot, nor any mention of prerequisites or scope (e.g., all datasets vs one). The agent must infer appropriate usage purely from the name.

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