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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, and the closing line 'Läser bara, ändrar inget' largely restates that. However, the description adds real value beyond annotations by enumerating what the payload contains (supplier, OCR, dates, lines with account/VAT, remaining balance in öre, voucher number), which tells the agent the response is a full accounting detail. Minor redundancy with readOnlyHint keeps it from 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 sentences, front-loaded with purpose, then usage/alternative, then payload. The return-field enumeration is long but earns its place since no output schema exists. No filler sentences.

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 compensates by listing the key returned fields, and annotations already carry the safety profile. Purpose, alternative routing, safety and return content are all covered, so an agent has everything needed to invoke it correctly.

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 both parameters are documented with formats and example values plus how to obtain them (list_companies, list_supplier_invoices). The description alludes to 'fakturans id' but adds no syntax or meaning beyond the schema, 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 ('Hämtar en leverantörsfaktura med alla uppgifter') and explicitly distinguishes itself from the sibling list_supplier_invoices. An agent can tell it apart from the list tool 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 the exact selection condition ('Använd när du har fakturans id och behöver detaljer') and names the alternative with its condition ('för att hitta fakturor eller se flera, använd list_supplier_invoices'). Nothing is left to inference.

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