bokio_download_invoice

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context that the annotations cannot convey: the return payload (written path and byte count), which is important given there is no output schema. It does not restate the no-overwrite rule from the schema, but nothing in it contradicts the annotations.

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 compact sentences with zero waste. The action and destination are front-loaded, and the sibling disambiguation follows immediately.

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?

There is no output schema, and the description compensates by describing the return value (path and byte count). For a simple file-download tool with fully documented parameters and annotations covering safety, this is nearly complete; only error behavior (e.g. unknown invoice id) is left entirely to the schema.

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 all three parameters are already documented, including the savePath no-overwrite constraint and the companyId default. The description only echoes savePath as the destination and adds no syntax or format guidance beyond the schema, so the 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 (download), resource (a published invoice), and output format (PDF file) written to a named location. It also explicitly distinguishes itself from bokio_get_invoice, which returns data rather than a file, so an agent can choose between them without opening either 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?

Names the alternative tool (bokio_get_invoice) and the condition that selects it ('returns the invoice data instead'). The routing decision between retrieving data and downloading a file is fully spelled out.

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