Skip to main content
Glama
Sign In
vmware-storage

vmware-storage

by vmware-skills
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Remote

rescan_storage

Rescan ESXi host HBAs and VMFS volumes to discover newly presented LUNs and datastores after storage array or out-of-band SAN changes; previews blast radius unless confirmed.

Instructions

[WRITE] Rescan all HBAs and VMFS volumes on an ESXi host to discover newly presented LUNs and datastores.

Use this when a storage array presents new LUNs, or after out-of-band SAN changes. Not needed after add_iscsi_target / remove_iscsi_target — those rescan automatically. Without confirm=True this only previews: it returns blast_radius (the host, every adapter the rescan touches, the mounted VMFS volumes) and changes nothing. Show it to the user. Do not set confirm=True on your own because the user asked earlier — they have not seen the preview yet. Deletes nothing, but it is I/O-visible on the host and may take a minute or two with many paths. Refused when the host's storage view cannot be read. Returns a dict.

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": {
      "host_name": "<host_name>"
    },
    "name": "rescan_storage"
  }
}

Input Schema

NameRequiredDescriptionDefault
targetNoOptional vCenter/ESXi target name from config.
confirmNoFalse (default) returns the blast radius and changes nothing. True applies it.
host_nameYesESXi host name as shown in vCenter inventory (FQDN or IP). Errors if not found.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv2.5.0
    • removedInput schema / properties / dry_run
      Removed value: -{
-  "anyOf": [
-    {
-      "type": "boolean"
-    },
-    {
-      "type": "null"
-    }
-  ],
-  "default": null,
-  "description": "Deprecated alias for confirm; removed in the next minor release. dry_run=False acts, dry_run=True previews.",
-  "title": "Dry Run"
-}
  2. Addedv2.0.0

TDQS

A4.8/5.0
Behavior5/5

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

Beyond annotations, it discloses the two-step preview/apply behavior, the exact blast-radius contents, the I/O visibility and possible duration, the fact that nothing is deleted, and the refusal condition. The guardrail against setting confirm=True without showing the preview is especially valuable for a write operation.

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

Conciseness5/5

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

The description is front-loaded with a [WRITE] tag and the core action, then proceeds through usage, preview behavior, safety warnings, and failure conditions. Despite its length, every section earns its place for a risky storage operation.

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

Completeness4/5

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

Given no output schema, the description explains the preview return as a blast_radius containing host, adapters, and mounted VMFS volumes, but the confirmed/apply return is only summarized as a dict. The optional target parameter is also left to the schema, but overall the definition is complete enough to call correctly.

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

Parameters4/5

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

Schema coverage is 100%, so host_name and confirm are already documented. The description adds useful meaning around confirm by explaining the preview return contents and the interaction policy of showing the blast radius to the user before applying, though it does not discuss the optional target parameter.

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

Purpose5/5

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

The description states a specific verb and resource: rescan HBAs and VMFS volumes on an ESXi host to discover new LUNs and datastores. It also distinguishes itself from sibling operations by noting that add_iscsi_target/remove_iscsi_target rescan automatically.

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

Usage Guidelines5/5

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

It gives explicit when-to-use guidance: after a storage array presents new LUNs or after out-of-band SAN changes. It also states when the tool is not needed and explains the confirm-preview workflow that must be shown to the user before applying.

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

Deploy Server

Other Tools