List Running VMs

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds the behavioral detail that VMs started by other users (e.g., root) are not shown unless run with sudo, which is important for users to interpret results. This goes beyond the structured annotations.

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 concise: it states the purpose, enumerates the return fields, and adds a caveat in a bulleted list. The structure is front-loaded with the main action and easy to scan.

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 the tool's simplicity (0 parameters, no output schema), the description fully covers what is returned and the important usage caveat. It is complete enough for an agent to select and invoke it correctly.

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?

The tool accepts zero parameters per the input schema, and the description appropriately does not need to add parameter semantics. The baseline score of 4 applies because schema coverage is 100% and no parameters 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 uses the specific verb 'List' with the resource 'currently running VMware Fusion virtual machines,' clearly distinguishing this from sibling tools like fusion_list_all. It also states the return values (count, paths, display names), making the purpose unambiguous.

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 clarifies that only VMs started by the current user are shown, which is a useful context for when to invoke this tool. However, it does not explicitly mention alternatives like fusion_list_all for listing stopped or all VMs, so there is no direct comparison or exclusion.

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