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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. Beyond restating purpose and citing the endpoint, the description adds no behavioral context — no pagination behavior, no default page size, no note on whether the root folder can contain nested folders.

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?

Two compact sentences with the purpose front-loaded followed by the concrete API reference; nothing is wasted. The doc URL is a legitimate addition rather than filler.

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?

Because annotations cover safety and an output schema covers return shape, the description doesn't need to explain results. It still leaves gaps an agent needs to call this correctly: undocumented pagination parameters and no routing signal versus the several other inbox-related tools.

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 only 40%: page, limit, and offset are bare typed fields with no descriptions, and only sortby/sortorder are documented. The description compensates for none of this, giving no hint about pagination semantics or valid sort fields for this resource.

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 concrete operation ('Retrieve the root folder') and pins it to a specific Fortnox endpoint (GET /3/inbox) with a docs link, so an agent knows exactly what resource is fetched. It does not, however, disambiguate from close siblings such as get_inbox or list_unprocessed_inbox, and the 'root folder' phrasing sits slightly awkwardly against the name list_inboxes.

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 when-to-use guidance at all — no indication of when this is preferred over get_inbox, list_unprocessed_inbox, or list_archives, all of which appear in the sibling list. The agent must infer selection purely from tool names.

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