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

Annotations only give generic hints (readOnlyHint=false, idempotentHint=false); the description adds real behavior: it discloses that the operation posts ('KODEN postar'), that it zeroes VAT accounts against the accounting account, that scope 'book' is required, and that a booking cap (0 = unlimited) can block it. This is meaningful disclosure beyond the structured fields, though reversibility/undo is not addressed.

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?

Compact and front-loaded: purpose first, then mechanism, then constraints, then arguments. No filler sentences, though the trailing 'Argument:' list partly duplicates the schema.

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 an irreversible-looking posting tool with no output schema, the description covers scope, cost/cap guard, what gets posted, and the argument set. Missing only failure/state preconditions and whether the approval can be undone, which is a modest gap.

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 (with a list_companies hint). The description compensates partially by explaining that key is a 'periodnyckel' and year is optional, which the schema does not say. That is useful but shallow, leaving formats and how to obtain the period key unstated.

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 pair ('Godkänn och bokför') and resource ('momsavräkningen för en period') and even describes the mechanism ('nolla momskontona mot redovisningskontot'), which separates it from read-only siblings like get_vat_return and list_vat_periods. It stops short of explicitly naming those siblings, so not a 5.

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?

Context is implied (a period-based VAT reconciliation that must be booked) and two hard prerequisites are given: scope 'book' and a booking cap that must not be exceeded. However, it never states when to choose this over get_vat_return or list_vat_periods, nor what state a period must be in before approval.

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