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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the underlying endpoint (GET /1.3/storage[/{kind}]) and the fact that omitted `kind` returns everything accessible, but says nothing about result size, pagination, or authorization requirements.

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?

Three dense, front-loaded segments: resource scope, filter semantics, underlying API path. No filler sentences, and the most decision-relevant information (what it lists, how to narrow) comes first.

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 output schema, the parenthetical field list (uuid, title, type, tier, size GB, state, zone, labels) usefully tells the agent what a result contains, and the filter semantics are covered. Missing only secondary details like pagination or auth scope, which are minor for a read-only list tool.

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%, so the baseline is 3, but the description adds real meaning the enum alone does not: it glosses each `kind` value (private = yours, public = UpCloud-provided, normal = disks) and explains the private/public axis. The `label` filter is fully documented in the schema.

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 the resource concretely and enumerates what counts as a storage device (disks, backups, CD-ROM images, OS templates), which is a specific scope. It does not explicitly distinguish itself from near siblings such as upcloud_get_storage (single item) or upcloud_list_object_storages, so sibling differentiation is left to inference.

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?

Usage is only implied: the `kind` values and the schema's 'Omit for every accessible storage' convey the filtering options, but the description never states when to reach for this tool versus upcloud_get_storage or upcloud_list_object_storages. No exclusions or prerequisites are given.

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