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

Annotations already declare readOnly, idempotent, non-destructive, and non-open-world, so the safety profile is free. The description adds real value beyond that: results are computed server-side from live Fortnox data and cover all pages, which tells the agent the output is complete rather than paginated/previewed.

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, front-loaded with the scope and the enumerated outputs, then the example question. The Fortnox API URL is marginal filler but doesn't distract materially.

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 full schema coverage, existing annotations, and an output schema, the description only needs to establish scope and trustworthiness of the data — both are covered. A small gap remains: the description is in Swedish while the tool name is English, and it never says what happens when no card account matches the default heuristic.

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 schema already documents the max cap (10 default, 20 maximum), the account default heuristic, and the fromdate/todate defaults. The description adds nothing about parameters, 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+resource in Swedish: reconciling corporate-card purchases in a period against receipts, with the three concrete outputs (missing documentation, receipt-to-purchase matching, unbooked receipts). This distinguishes it in scope from the other reconcile_* siblings (ledgers, supplier statements), though it never names them.

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 embedded example question ("Stäm av företagskortet för september.") gives an implied trigger for the tool, but there is no explicit when-not guidance and no naming of alternative tools such as reconcile_ledgers or prepare_inbox_receipts that an agent might confuse this with.

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