vsphere_get_vm_summary_by_host

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

Annotations already declare readOnlyHint and idempotentHint. The description adds value by detailing what the summary includes (VM counts, powered-on count, vCPU, memory), giving more behavioral context than just the annotations. No contradiction.

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

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

The description is two concise sentences, front-loaded with the action 'Aggregate', and every sentence adds meaningful detail. No wasted words.

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

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

Given no parameters, a read-only annotation set, and an output schema present, the description fully covers the tool's purpose and use case. It is complete for a straightforward read-only aggregation tool.

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

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

There are zero parameters, so the baseline is 4. The description doesn't need to add param details as none exist.

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

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

The description clearly states the tool aggregates VM counts and allocated resources per ESXi host, which is a specific verb+resource. It distinguishes itself from siblings like vsphere_list_hosts (list hosts) and vsphere_list_vms (list VMs) by focusing on per-host summary data.

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

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

The description provides clear context: 'A quick capacity/placement overview' indicates when to use this tool. It doesn't explicitly list alternatives or exclusions, but the use case is well implied, making it a 4.

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