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

Adds meaningful context beyond the annotations: no voucher is created ('utan verifikat') and a 'book' scope is required. This complements idempotentHint=true and destructiveHint=false by clarifying that the operation mutates year-end state without producing an accounting entry. No contradiction with annotations.

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 action and then the qualifying condition and requirements. No filler, though the dense mixed-language phrasing slightly reduces readability.

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 3-parameter mutation tool with no output schema, the description covers the action, the when, the scope requirement, and the valid step values — everything needed to call it correctly. Only the year parameter and return behavior are left implicit, which is minor given no output schema exists.

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 coverage is only 33% (only orgnr is documented), and the description compensates by enumerating the step values (periodiseringar|dispositioner|aktuell_skatt|arets_resultat), which the schema does not declare as an enum. This is real added value over the structured fields, though year remains undocumented.

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: acknowledging a year-end step as not applicable, explicitly 'utan verifikat' (without voucher), which distinguishes it from the booking siblings like book_year_end_step and undo_year_end_step. It does not name those siblings directly, so the contrast is implied rather than explicit.

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 a concrete when-to-use condition: a year-end step that is not applicable, e.g. no accruals or a zero amount. It does not explicitly exclude or name the alternative (booking the step), leaving the agent to infer that a real posting should go through book_year_end_step instead.

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