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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely new context: the figures are computed server-side from live Fortnox data and aggregated 'over all pages', telling the agent it need not paginate or stitch results itself. Return shape is left to the output schema.

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?

Front-loaded with the figure list, then a usage example, then implementation provenance — a sensible order with little filler. The Fortnox API URL is marginal noise that a reader gains nothing from.

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 one optional parameter, full schema coverage, an output schema, and annotations covering the safety profile, the description supplies everything an agent needs: what is measured, for whom, and that computation is server-side and complete. No material gap remains.

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 100% and the single optional date parameter is documented there as a fiscal-year selector (ÅÅÅÅ-MM-DD). The description says nothing about the date parameter or what its absence means, so it adds no meaning beyond the schema — the baseline 3 for high coverage 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?

Enumerates the concrete figures returned (omsättning, resultat, marginal, kassa, kundfordringar, leverantörsskulder) and states scope as 'ett bolag eller alla', so the agent knows exactly what resource this produces. It does not differentiate itself from close siblings such as get_profit_and_loss, get_management_report or get_balance_sheet, which keeps it from a 5.

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?

The example question ('Hur går det för bolaget just nu — i siffror?') gives a concrete trigger context for selecting this tool. No when-not conditions or named alternatives are offered, so an agent comparing it against the many other financial-report siblings must infer the boundary itself.

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