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

With no annotations, the description carries the full burden; it does reveal that results include size limits and usage, which is useful behavioral context for a list call. However, it never states the operation is read-only, nor does it mention pagination, ordering, or auth requirements for a listing that could be large.

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?

A single well-formed sentence with the resource and returned fields front-loaded and no filler. Nothing redundant or wasted.

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 zero-parameter read tool with no output schema, the description does indicate what comes back (size limits and usage). It is a bit thin on how this differs from managed volumes and lacks any pagination/return-shape detail, but the essentials are present.

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 tool takes zero parameters, so there is no parameter semantics to explain and the baseline is 4. The description correctly implies the listing is unfiltered and covers the caller's own volumes.

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?

States a specific verb (List) and resource (the user's standalone storage volumes) plus the data returned (size limits and usage). The word 'standalone' implicitly distinguishes it from the sibling list_managed_volumes, but the contrast is never made explicit.

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?

No guidance on when to use this versus list_managed_volumes or the other list_* siblings, and no prerequisites or exclusions stated. The agent must infer usage entirely from the name and the adjective 'standalone'.

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