mcp-vmwhere

列出 Datastore

list_datastores

Read-onlyIdempotent

Lists vCenter datastores with capacity, free space, used percentage, and high-utilization counts, sorted by utilization to support storage capacity monitoring.

Instructions

列出 vCenter 中的 Datastore(儲存),附上算好的容量與使用率。

回傳: total: Datastore 數量(直接引用,不要自己數)。 total_capacity_GiB / total_free_GiB / overall_used_pct: 全部合計。 used_pct_at_least_90 / used_pct_at_least_80: 使用率達 90%／80% 以上的數量。 datastores: 每個 datastore 的 id、名稱、類型、capacity/free_space(位元組)、 capacity_GiB、free_GiB、used_pct(已用百分比),已依 used_pct 由高到低排序 (容量為 0 或未知者排最後)。

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_datastores"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description	Default
`total`	Yes
`sorted_by`	Yes
`datastores`	Yes
`total_free_GiB`	Yes
`overall_used_pct`	Yes
`total_capacity_GiB`	Yes
`used_pct_at_least_80`	Yes
`used_pct_at_least_90`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 7, 2026

TDQS

A4/5.0

Behavior4/5

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

The annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: the datastores array is pre-sorted by used_pct descending with zero/unknown capacities pushed to the end, and the caller should quote 'total' rather than counting entries itself.

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

Conciseness3/5

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

The purpose is front-loaded in the first line, which is good, but the following block enumerates return fields (total, total_capacity_GiB, used_pct_at_least_90, per-item ids and GiB fields) that the output schema already defines, so much of the text restates structured data. Only the sorting rule and the 'don't count it yourself' instruction genuinely earn their space.

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?

With no parameters, full annotation coverage, and an output schema, the description covers everything an agent needs: what it returns, that it is pre-aggregated, and how results are ordered. Minor gaps remain, such as what happens on permission failure or whether powered-off/unmounted datastores are included, but nothing blocks a correct call.

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?

The tool takes no parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The description correctly does not invent parameter guidance.

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 first sentence names a specific verb+resource pair (list Datastore in vCenter) and adds the value proposition that capacities and usage percentages are pre-computed. That scope cleanly separates it from siblings such as list_vms, list_hosts, and list_clusters without needing to name them.

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

Usage Guidelines3/5

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

Usage is only implied: an agent can infer that this is the read-only inventory call for storage, since it takes no parameters and lists everything. There is no explicit statement of when to prefer it over other inventory tools or any exclusion, but with zero parameters and no overlapping sibling there is little ambiguity to resolve.

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

Deploy Server