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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds genuinely new behavioral detail the annotations cannot carry: which invoice states are excluded (ej bokförda, makulerade, betalda) and the sort order. The closing 'Läser bara, ändrar inget' is redundant with the annotations but not harmful.

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 sentences: purpose, routing, exclusions/return shape. Front-loaded with the core purpose and no filler, though the final read-only sentence is redundant padding given the annotations.

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?

There is no output schema, and the description compensates by enumerating the returned fields (namn, utestående och förfallet belopp i öre, antal fakturor), the ordering, and the total. Combined with the exclusions, an agent knows both what it gets and what is omitted.

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?

With a single parameter at 100% schema coverage, the schema already documents orgnr format and where to obtain it (list_companies). The description adds no parameter-level meaning beyond that, 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 ('Visar utestående kundfordringar per kund') and immediately narrows scope with what is measured (obetalt vs förfallet). It explicitly distinguishes itself from the sibling list_customer_invoices, so an agent can separate the two without opening either 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 an explicit when-to-use ('Använd för frågor som vilka kunder som är skyldiga bolaget pengar') and names the alternative for the adjacent case ('för fakturorna i detalj, använd list_customer_invoices'). Nothing is left for the agent to infer about routing.

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