qemu_vm_metrics

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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description discloses a critical behavioral trait: the tool keeps the VM locked and requires vm_unlock to be called afterward. This is essential context that annotations do not provide.

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 terse sentences: the first states the action and resource, the second states a critical follow-up. No wasted words; it is front-loaded and direct.

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?

For a simple read-metrics tool with annotations and a single parameter, the description provides the essential facts: what it reads and the lock/unlock contract. It doesn't detail return values, but no output schema exists and the tool's purpose is straightforward. It could mention the metric categories, but is sufficient for correct invocation.

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 schema has one parameter (vm_id) with no description, and the description does not mention it at all. With 0% schema description coverage, the description should compensate, but it adds no meaning beyond the parameter name and pattern. The parameter is simple, but the description still fails to provide any semantics.

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 a specific verb 'Read' with a clear resource: 'managed QEMU process and QMP metrics.' This distinguishes it from sibling tools like qemu_vm_status or qemu_vm_list, and the scope is 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 implies usage context by stating 'VM remains locked by this session; call vm_unlock when finished,' which tells the agent this is part of a lock-hold workflow. It doesn't explicitly name alternatives or exclusions, but it provides clear operational context.

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