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

Beyond the annotations (readOnly=false, destructive=false, openWorld=true) it discloses that the invoice is marked as sent, that failures surface under the Misslyckade filter and in the next list_invoices call, and that it reaches other people requiring per-call confirmation. That is rich behavioral context the structured fields 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?

Front-loaded with the core action and methods, and each later sentence adds a distinct fact (activation caveat, failure visibility, confirmation policy, auth). Slight redundancy between the first and second sentences restating 'send a booked invoice' keeps it from a 5.

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?

Complete for a mutation/send tool: it covers the action, method selection, failure handling, confirmation behavior, and the API key requirement. No output schema exists, but failure visibility is explained, so nothing an agent needs is missing.

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 the enum and invoice_number are already documented; baseline would be 3. The description adds meaning the schema lacks by noting e_invoice only functions when activated in invoicing settings, giving an operational constraint on the method parameter.

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 (Send) and resource (booked invoice) plus the three delivery methods, and the 'booked invoice' qualifier cleanly separates it from create_invoice and bookkeep_invoice. An agent can tell what this does without opening the schema.

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 clear context and preconditions: the invoice must already be booked, and e-invoice only works if activated in Fortnox settings. It does not explicitly name alternative siblings (e.g. create/bookkeep) or state when not to use it, so it falls short of a 5.

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