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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description reinforces this in plain language ('Läser bara, ändrar inget'), which is largely redundant. Its real added value is describing the payload shape (rows, öre amounts with debit positive/credit negative, underlag), which annotations do not cover. Auth requirements and error behavior are still unstated.

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 front-loaded sentences: purpose, usage routing, return contents. The return enumeration is long but justified in the absence of an output schema, and no sentence is wasted.

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 must carry the return contract, and it does: voucher header fields plus line-level fields (account, amount in öre with sign convention, VAT code) and underlag. Combined with annotations covering the safety profile, an agent has everything needed to call and interpret the result.

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%: the schema already documents orgnr (format plus example) and voucher_id (integer, obtained via list_vouchers). The description adds no parameter-level detail 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?

The description states a specific verb and resource ('Hämtar ett bokfört verifikat') and immediately scopes what is included ('med alla rader och kopplade underlag'). It explicitly distinguishes itself from the sibling list_vouchers, so an agent can route correctly without opening the 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?

It gives an explicit use condition ('Använd när du har verifikatets id') and names the alternative for the opposite case ('för att hitta verifikat, använd list_vouchers'). This is a complete when-to-use / when-to-use-something-else instruction with nothing left to inference.

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