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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description still adds meaningful behavioral context: it is computed server-side from live Fortnox data and runs across all pages, telling the agent results are fresh and paginated. It does not detail cost or rate limits, keeping it below 5.

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 core check is front-loaded in the first sentence, followed by an example and a short data-provenance note. The API URL reference is slightly extraneous but the overall length is justified and well-ordered.

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 an output schema present, return values need not be explained. The description covers what is compared, that it looks for missing attachments, that data is live, and that all pages are included, giving the agent enough to call it correctly. Minor gaps remain around whether results are flagged vs. enumerated.

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%, so max, borjan, from_date, to_date and leverantor are all documented in the schema itself. The description adds no parameter-specific syntax or format guidance beyond what the schema already provides, so the baseline of 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?

The description states a specific verb (check/match) and resource (supplier invoices vs. their attachments) plus the exact fields compared: amount, VAT, due date, OCR and bankgiro, and which lack attachments. It is clearly distinguishable from list_supplier_invoices and find_duplicate_supplier_invoices, though it does not explicitly name the closest sibling, find_vouchers_without_attachments.

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?

An embedded example question ("Stämmer leverantörsfakturorna i september mot sina underlag? Saknas någon bilaga?") implies when the tool applies, which is helpful context. However, there is no explicit when-to-use/when-not guidance and no alternative tool is named for overlapping cases.

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