system_info

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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint. The description adds a valuable non-obvious behavioral fact: the VM remains locked by this session and must be unlocked with vm_unlock. This goes beyond the structured annotations and is critical for correct usage.

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?

Two concise sentences: the first states the core functionality, the second conveys the essential lock-lifecycle warning. No filler, repetition, or unnecessary detail.

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?

The tool has one well-documented parameter, safety-related annotations, and no output schema. The description adds the missing lock context and lists the information categories returned, which is sufficient for an agent to invoke it and finish the workflow 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 schema fully documents the only parameter, vm_name, including its format and configuration source. Since schema description coverage is 100%, the description does not need to add parameter details; 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?

Description identifies a concrete action (read) and a specific resource: detailed guest OS, code-page, display, and build information. It is clear what the tool operates on, but it does not explicitly differentiate itself from sibling status/information tools like vm_status or qemu_vm_status.

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 intended use is implied: call this when detailed guest system or build information is needed. The lock caveat gives useful workflow guidance ('call vm_unlock when finished'), but there is no explicit comparison with alternatives or when-not-to-use guidance.

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