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

Annotations already cover the read-only/safe profile, and the description adds genuinely non-obvious behavior: payment status and outstanding amount are gated behind a paid package and payment-status permission and are omitted otherwise, results are capped at 100 per page with a cursor for the next page, and a Cotlet API key with app access is required.

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?

The auth/package/pagination sentences earn their place and are front-loaded, but the second sentence ('Lists the invoices in Outgoing invoices, newest first, the way the list in the app shows them') largely restates the first sentence's 'Outgoing invoices ... newest first', creating redundancy.

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?

With no output schema, the description correctly carries the burden of describing the return shape (fields listed), pagination (100/page plus cursor), and the field-omission caveat. It is nearly complete, though it leaves the actual filter behavior of the Szűrő button unspecified.

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 100%, so all six parameters are already documented in the schema. The description only alludes to filtering ('same kind of filters as the Szűrő button') without adding format or semantics beyond the schema, which matches the baseline 3.

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 (list outgoing invoices) and goes further by naming the returned fields (number, buyer, dates, gross amount, payment status) and ordering (newest first), which clearly separates it from the single-invoice get_invoice sibling. It never names the sibling explicitly, so it stops short of 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?

Gives useful context that it mirrors the app's invoice list and the Szűrő button filters, implying it is the browsing tool. It never states when to prefer this over get_invoice or when not to use it, so usage is implied rather than explicit.

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