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

No annotations are provided, so the description carries the full behavioral burden, and it says nothing about whether 'open' is read-only or mutates state (e.g. marks the cube as opened, creates a session, requires consent given cube_consent exists as a sibling). No permission, side-effect, or error behavior is disclosed.

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 single short sentence is front-loaded and free of padding, but it is under-specified rather than concise: the brevity removes information an agent needs instead of removing waste.

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?

With no annotations, no output schema, and no documented parameters, the description is the only source of behavior and it supplies essentially none. For a tool whose verb is ambiguous within a large sibling set, far more disclosure is required.

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 0% for the single required parameter cube_id. The phrase 'by id' only confirms that cube_id identifies the cube — it adds no format, source, or lookup guidance (e.g. where to obtain the id, whether it is the same id returned by cube_search).

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 names a specific resource (a cube) and a specific operation (open it, by id), so an agent can tell it apart from cube_create or cube_search at a rough level. But 'open' is not a well-defined verb — it could mean retrieve, activate, join, or establish a session — so the actual purpose stays vague.

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?

There is no statement of when to use this tool versus cube_search (to find a cube), cube_create (to make one), or cube_install, even though those siblings occupy adjacent semantic space. The agent must infer usage from the name alone.

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