vmware-vks

list_namespace_storage_usage

Read-onlyIdempotent

List PersistentVolumeClaims and their storage usage in a vSphere Supervisor Namespace to check each PVC's status, capacity, and storage class.

Instructions

[READ] List PersistentVolumeClaims and storage usage inside one vSphere Namespace.

Via the Supervisor K8s API. Returns the family list envelope: {namespace, items: [{name, namespace, status (Bound / Pending / Lost), capacity ('10Gi'), storage_class}], returned, limit, total, truncated, hint}. Every PVC comes back in one call, so truncated is always False. Run list_namespaces first for the namespace; use list_supervisor_storage_policies instead for policy-level rather than PVC-level information. 'pvcs' and 'pvc_count' are deprecated pre-1.8.0 aliases of 'items' and 'returned', removed in 2.0 — read 'items'.

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": {
      "namespace": "<namespace>"
    },
    "name": "list_namespace_storage_usage"
  }
}

Input Schema

Name	Required	Description	Default
`target`	No	vCenter in config.yaml; omit for the default.
`namespace`	Yes	Namespace to inspect.

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv1.8.14Aug 30, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```
- addedInput schema / properties / namespace / description
```
Added value: +"Namespace to inspect."
```
- addedInput schema / properties / target / description
```
Added value: +"vCenter in config.yaml; omit for the default."
```
Addedv1.5.26May 20, 2026
Removedv1.5.23May 20, 2026
First observedv1.3.2Mar 27, 2026

TDQS

A4.9/5.0

Behavior5/5

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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond that: it names the API path ('Via the Supervisor K8s API'), documents the full return envelope, explains that truncated is always False, and warns about deprecated aliases removed in 2.0.

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 dense but well-organized: purpose, return shape, behavioral guarantee, prerequisite, and deprecation note. Nothing is filler, and the most important information is front-loaded.

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

Completeness5/5

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

Despite having no output schema, the description fully specifies the return envelope and field semantics. It also covers prerequisites, the alternative tool, the optional target parameter, and backward-compatibility caveats, making the tool safely callable by an agent.

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 the baseline is 3. The description adds meaning by emphasizing the namespace scope and telling the agent to run list_namespaces first to obtain a valid namespace value. It does not add much about the target parameter, but the schema already handles that fully.

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 opens with a specific verb and resource — 'List PersistentVolumeClaims and storage usage' — and scopes it to 'one vSphere Namespace'. It also distinguishes itself from the sibling tool list_supervisor_storage_policies by explicitly noting the PVC-level vs policy-level difference.

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?

The description gives explicit routing guidance: 'Run list_namespaces first for the namespace' and 'use list_supervisor_storage_policies instead for policy-level rather than PVC-level information.' This clearly tells the agent when to use this tool versus the relevant sibling.

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