Restart Cube

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

The description goes well beyond the annotations by disclosing that this is a cold, asynchronous restart where the hypervisor process is stopped and relaunched. It explicitly states that disk state is preserved, only the kernel changes, and that the Cube must be running. These details align with destructiveHint=false and readOnlyHint=false, and add meaningful operational context about side effects and execution semantics.

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 tightly structured: each sentence contributes a distinct piece of information — the operation type, the mechanism, the unique use case, the effect on disk/kernel, and the precondition. There is no filler or redundancy, and the most important information is front-loaded in the first sentence.

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 relatively simple tool (2 parameters, no nested objects, no output schema), the description covers all essential aspects an agent needs: the operation, why it exists, when to use it, its side effects, and its precondition. The absence of an output schema is not a significant gap because the description already indicates the operation is asynchronous and the key outcome is the kernel refresh. No critical information is missing.

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%, with cubeId and spaceId both already documented in the schema. The description adds no parameter-specific meaning beyond what the schema provides, so the baseline score of 3 is appropriate. It does not introduce any confusion or new parameter behavior.

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 states a specific verb and resource with precision: 'Restart a running Cube — a COLD restart (asynchronous).' It clearly differentiates this operation from an in-guest reboot and from related operations like power_off_cube, wake_cube, or restore_cube by explaining that it relaunches the hypervisor process and only changes the kernel while preserving disk state. The unique use case (picking up a refreshed guest kernel after a platform image update) is also explicitly stated.

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 gives an explicit when-to-use condition: 'This is the only way a Cube picks up a refreshed guest kernel after a platform image update.' It also explains why an alternative approach (issuing `reboot` inside the Cube) cannot achieve this, which is clear when-not guidance. The precondition 'The Cube must be running' further tells the agent when it is safe to invoke the tool.

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