List Cubes

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is carried structurally. The description contributes the scoping behavior (results bounded to one Space) and the domain vocabulary, but says nothing about result volume, pagination, ordering, or whether an empty Space returns an empty list versus an error — the practical behaviors an agent would want before calling.

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?

One short sentence, front-loaded with the verb and the resource, with zero filler. However, the brevity is borderline under-specification for a listing tool: nothing is wasted, but nothing extra is offered either.

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?

There is no output schema, so the description is the only place an agent could learn what a listing returns — yet it says nothing about the shape of returned Cube objects, whether the list is paginated or truncated, or whether the call requires authentication. For a simple zero-required-parameter read tool this is adequate but leaves real gaps.

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 coverage is 100% and the single spaceId parameter is already documented in the schema, including the KROVA_SPACE_ID fallback. The description only reinforces that the listing is Space-scoped; it adds no new meaning about the parameter's format or behavior. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('List all Cubes') and even disambiguates the domain term by glossing Cubes as Firecracker microVMs, which an agent could not infer from the name alone. It also scopes the result to a single Space. It stops short of explicitly contrasting with the sibling get_cube (single-instance retrieval), which keeps it at 4 rather than 5.

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 use case is implied by 'List all ... in a Space', and the existence of get_cube makes the enumeration vs. single-fetch split inferable, but the description never states when to prefer this over get_cube or the region/image listing siblings. No exclusions, prerequisites, or pagination caveats are given.

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