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

Goes well beyond the readOnly/idempotent/non-destructive annotations by disclosing a hard precondition (postcode and city must be known, otherwise an error naming the missing fields), the return payload shape, the ISO 8859-1 encoding Skatteverket requires, and that the tax follows previously saved choices. 'Sparar och skickar inget' also reinforces the read-only annotation.

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 action and its output, then routing, prerequisite, return format, and non-effects. Six short sentences each carry distinct information, though the tax/encoding asides edge slightly toward over-coverage for a single tool.

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?

For a no-output-schema tool, the description explains the returned content (file text plus applicable year) and the encoding needed to use it. Combined with the explicit error behavior, an agent has everything required to call it and handle failures 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%: both 'year' (with its end-of-fiscal-year convention and default) and 'orgnr' (format and how to obtain it via list_companies) are fully documented in the schema. The description adds the postcode/postort precondition, which is a data requirement rather than a parameter, 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: produces INK2 as SRU files (INFO.SRU/BLANKETTER.SRU) for a fiscal year, populated from the year-end accounts. It explicitly names the sibling it is not (read_tax) so an agent can distinguish them 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 ('Använd när användaren själv ska lämna in inkomstdeklarationen hos Skatteverket') and an explicit alternative with its own condition ('för själva skatteberäkningen, använd read_tax'). 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.