Save an invoice PDF

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

Goes beyond annotations meaningfully: it clarifies that although a file is written to the local filesystem, the tool never mutates the invoice's send state (preventSendBy) and is read-only towards sevDesk. This resolves the potential confusion between a local disk write and a remote mutation.

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, front-loaded with the core action and followed by the key behavioral caveat. No wasted words.

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?

For a simple two-parameter tool with no output schema, the definition is nearly complete. Minor gap: it doesn't state the returned filename or path, which an agent might need for follow-up operations, but this is small.

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 both parameters are documented in the schema. The description adds the allowlist constraint for `directory`, but nothing extra for `invoiceId`. Baseline 3 is appropriate when the schema carries the parameter semantics.

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?

Specific verb+resource: 'Fetch the rendered PDF of an invoice and save it into a directory'. Clearly distinguishes from siblings like sevdesk_mark_invoice_sent or sevdesk_list_invoices, which do not produce a PDF artifact.

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?

States the precondition that the target directory must come from the SEVDESK_RECEIPT_DIRS allowlist, and reinforces it via the 'preventSendBy' note. No explicit alternative routing (e.g. when to use a download vs. upload path), but the usage context is clear.

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