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

Goes well beyond the annotations: it discloses that a booked step is undone via a reversing mirror voucher in the same series with the original left untouched, that the step is reopened, and that a reconciled step is reset to pending. It also states the required scope (book). This is exactly the mutation-mechanics and auth context the readOnly/destructive hints cannot convey, and it is consistent with destructiveHint=false.

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, then mechanics, then permission requirement, then arguments — a sensible order with no filler. It is dense but each clause carries information; the main cost is the mixed-language surface against English sibling names.

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?

No output schema exists, and the description covers the mutation mechanism, the resulting state, the required scope, and the accepted argument values, which is enough to call it correctly. It omits error/failure behavior (e.g. what happens if the step is in neither state) and any response shape, leaving a minor gap for a non-idempotent mutation.

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 schema coverage at only 33% (only orgnr is documented in-schema), the description compensates by naming all three arguments and supplying the allowed step values (periodiseringar|dispositioner|aktuell_skatt|arets_resultat), which the schema lacks entirely (0 enums). It does not clarify the expected year format or orgnr handling beyond the schema, but it substantially fills the coverage gap.

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 ('Ångra ett årsavslutssteg') and then distinguishes the two operating modes by input state (BOKFÖRT vs KVITTERAT), which no sibling (book_year_end_step, skip_year_end_step, reverse_voucher) shares. An agent can tell this apart from the other year-end tools without opening any 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 clear conditional context: it applies to steps that are booked or reconciled, and explains what each state triggers. It does not, however, explicitly say when to prefer this over book_year_end_step, skip_year_end_step, or reverse_voucher, so routing versus the closest siblings 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.