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

Annotations already declare write/non-destructive/non-idempotent, so the bar is lower. The description adds real value beyond them: the scope requirement, the booking-limit constraint, that 'KODEN postar' (the code performs the posting), and the default cash account. It stops short of stating reversibility or what happens on re-invocation.

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?

Dense and front-loaded: purpose, accounting entry, prerequisites, then arguments in one compact block. Telegraphic phrasing is efficient rather than padded, though the argument list crowds the prose slightly.

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 mutation tool with no output schema, the description covers the accounting effect, the auth/limit prerequisites, and every parameter including the optional one. An agent has enough to invoke it correctly, barring explicit idempotency/reversal behavior.

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 only 20%, so the description must compensate, and it does list all five args including the pay_date format (YYYY-MM-DD) and the bank_account default/meaning ('likvidkonto som debiteras, default 1930'). It leaves amount_ore's unit and invoice_id semantics to the schema, but the added format and default detail lift it above baseline.

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 ('Bokför en INbetalning på en kundfaktura') and even gives the resulting accounting entry (D likvidkonto / K 1510). This clearly distinguishes it from reverse_customer_payment and register_supplier_payment.

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?

Provides prerequisites ('Kräver scope book', booking limit must not be exceeded), which is genuine usage context. However, it never says when to choose this over alternatives such as reverse_customer_payment or book_customer_invoice; the routing guidance is only implied.

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