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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond them: VM names are not unique (disambiguate via identifier/ID), VMs share an IPv6-only private network with containers in the environment, and first-boot image download can make things appear stuck.

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?

Front-loaded with purpose then filters then usage guidance, and each sentence carries information. It is slightly dense with the VM/container networking aside, but nothing is filler.

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?

With no output schema, the description correctly summarizes the returned fields, and it covers filtering and the name-uniqueness caveat. It stops short of mentioning pagination or result size behavior for a list tool that could return many VMs.

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?

Schema description coverage is 100%, so the schema already documents state, environment, context, and conversation_id. The description restates the environment/state filtering but adds no syntax or format detail beyond the schema, so the baseline 3 is appropriate.

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?

States a specific verb and resource ('List virtual machines on the hub') and enumerates what is returned (current state, image, resources, assigned public IPs). This clearly distinguishes it from siblings like list_containers and list_servers, which cover different resource types.

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?

Gives concrete usage contexts: checking whether a deploy or start finished, and finding a VM's ID before controlling it (i.e., before cycle_control_virtual_machine or run_vm_command). It does not explicitly name alternative tools or state when-not to use it, so it stops short of a 5.

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