Linux MCP Server

List block devices

list_block_devices

Read-only

Enumerate block devices on a local or remote RHEL host to inspect disks, partitions, and storage hardware for troubleshooting.

Instructions

List block devices on the system

Input Schema

TableJSON Schema

Name	Required	Description	Default
`host`	Yes	System to run on: 'localhost' for the system the MCP server runs on, or a remote host to connect to via SSH

Output Schema

TableJSON Schema

Name	Required	Description	Default
`total`	No
`blockdevices`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv1.7.0Oct 3, 2026

removedInput schema / properties / host / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

removedInput schema / properties / host / default
```
Removed value: -null
```

changedInput schema / properties / host / description

Previous value: -"Remote host to connect to via SSH"New value: +"System to run on: 'localhost' for the system the MCP server runs on, or a remote host to connect to via SSH"

addedInput schema / properties / host / examples

Added value: +[
+  "localhost",
+  "web1.example.com"
+]

addedInput schema / properties / host / type
```
Added value: +"string"
```
addedInput schema / required
```
Added value: +[
+  "host"
+]
```

Changed1 schema field changedv1.6.0Sep 4, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```
First observedv0.1.0Mar 11, 2026

TDQS

C2.9/5.0

Behavior2/5

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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, and an output schema exists to describe the result. The description adds nothing beyond that — no detail on remote-vs-local behavior (the host parameter allows SSH), no notes on what constitutes a block device, and no scoping caveats.

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?

One short, front-loaded sentence with no filler or redundancy. It is appropriately sized, though the terseness leaves little room for the routing detail an agent would benefit from.

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?

For a low-complexity, single-parameter read tool with annotations and an output schema, the description is adequate but minimal. It omits any differentiation from storage-related siblings like get_disk_usage, which is the main gap for an agent choosing between them.

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%, so the single host parameter is already fully documented in the schema, including the localhost/SSH distinction. Baseline 3 applies since the description adds no parameter semantics of its own.

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+resource ("List block devices") with a scope qualifier ("on the system"), so an agent knows exactly what it returns. It does not, however, distinguish itself from close siblings like get_disk_usage or get_hardware_information, which could also surface storage hardware.

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 when-to-use guidance, no exclusions, and no mention of alternatives such as get_disk_usage. The agent must infer the correct context from the tool name alone.

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