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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorld, so the safety profile is covered. The description adds a genuinely non-structured detail: the required OAuth scope 'invoices.read', plus the fact that results are paged — value the annotations do not carry.

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 short sentences, no filler, with the core action front-loaded ahead of the permission requirement. Nothing is wasted.

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?

All six parameters are optional and fully documented in the schema, and there is no output schema, so the description need only cover scope and intent. It does that, though it omits any hint of the response/pagination contract or the sibling distinction, which would round it out.

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 100%, including detailed offset/cursor paging semantics, embed scopes and field projection, so the schema does the heavy lifting. The description's 'with paging' only gestures at what the offset/limit params already document thoroughly, so baseline 3 applies.

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 ('List invoices with paging'), which is immediately clear. However, it does not distinguish itself from the sibling sellsy_search_invoices or sellsy_get_invoice, leaving the agent to infer the difference between a plain list and a filtered search.

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?

The only guidance is the prerequisite 'Needs invoices.read', which is useful auth context but not a usage rule. It never says when to prefer this over sellsy_search_invoices or when paginating vs fetching a single invoice via sellsy_get_invoice, so the selection logic is left implicit.

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