Create letter PDF

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description does a strong job: it reveals the fixed house layout (DIN 5008 address field, 25mm margin, fold/punch marks), the intended signature overlap ('The signature image intentionally overlaps the closing line'), and the return format (file path, page count, layout metrics, warnings). This is meaningful behavioral context beyond the schema.

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 description is compact (three sentences) and front-loaded with the core purpose. Every sentence earns its place: what it renders, the fixed-layout constraint, a notable quirk (signature overlap), and the return value. It is not padded with schema-echo.

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?

This is a complex tool (22 params, nested objects, no annotations, no output schema), yet the description covers the fixed layout constraint, the signature overlap behavior, and the return payload. The high schema coverage (86%) lets the schema carry the parameter details, and the description compensates for the format/layout context. The main gap is not naming sibling alternatives for when to choose this vs preview_letter, but the description is otherwise thorough for its complexity.

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 high at 86%, so the schema documents most parameters well. The description itself does not enumerate individual params (correctly, given coverage), but it does add behavioral semantics around the signature image and layout. Baseline 3 applies given high schema coverage; the description adds some value beyond it.

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 uses a specific verb+resource combination ('Renders a letter as a PDF file') with detail about the layout (DIN 5008, 25mm margin, fold/punch marks, bold subject). It clearly distinguishes from siblings like preview_letter through 'in the fixed house layout' and 'Pass content only, the layout is fixed.' This is specific and unambiguous.

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 gives a clear usage directive ('Pass content only, the layout is fixed') and notes when a profile should be used vs typing a sender (in the schema, not the description). However, the description does not explicitly state when to use this vs preview_letter, list_profiles, or get_din5008_spec, nor provide exclusion conditions. The context implies usage well but lacks explicit alternative differentiation.

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