Download an invoice file

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

Annotations declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine context: the side effect is writing a file to local disk, the call returns a file path, and the default destination is the Downloads folder. It does not, however, mention overwrite behavior or permissions.

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 tight sentences, front-loaded with the core action and outcome, with the default-location detail appended. No filler or repetition of the title.

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?

Output schema and annotations cover the return value and safety profile, so those need no description. The gaps are the undocumented 'id' parameter and the absence of any routing guidance among the many sibling invoice tools, leaving the definition only minimally complete for a 3-parameter tool.

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 33% (only 'directory' is documented). The description partially compensates by clarifying the pdf/xml choices and the Downloads default, matching both the format enum and directory default, but it says nothing about the required 'id' 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 (saves) and resource (PDF/XML e-invoice) and clarifies the outcome (file on this computer plus returned path). This implicitly separates it from get_invoice, which retrieves invoice data rather than writing a file, though no sibling is named explicitly.

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 description offers no when-to-use guidance, no prerequisites, and no direction on choosing between this and get_invoice or list_invoices. The context is inferable but the definition never states it.

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