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

readOnlyHint=true already establishes the safety profile, and the description adds real context: the state field can be transitional ('backuping') and the tool is intended for polling an in-progress backup. It does not mention failure behavior for an unknown UUID or any rate/latency caveats, so not a 5.

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 tight sentences, front-loaded with the returned-field summary, followed by usage and the underlying API path. The 'UpCloud: GET /1.3/storage/{uuid}' trailer is mildly redundant but cheap and helps map to the documented endpoint.

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 description carries the burden of describing returns, and it enumerates the meaningful response fields plus the polling use case. For a single-parameter read tool with annotations covering safety, nothing an agent needs to call it correctly 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?

Only one parameter, storage_uuid, and schema description coverage is 100%, so the schema already documents it fully. The description adds no syntax or format detail beyond the schema (it doesn't even restate the UUID), so the baseline 3 applies.

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 and resource ('Details of one storage') and enumerates the notable fields returned (size, tier, state, encryption, attachments, backups, backup_rule). The scope word 'one' distinguishes it from the sibling upcloud_list_storages, so an agent can route without opening the schema.

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?

Gives concrete when-to-use guidance: 'Poll this to follow a backup started with upcloud_create_storage_backup.' That ties it to a named sibling and a workflow. It lacks an explicit when-not-to-use (e.g. use upcloud_list_storages for enumerating many), so it falls short of a 5.

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