Render a saved template to PDF

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

With no annotations, the description carries the full burden and does so: it discloses the free-plan watermark ('expected, not a bug'), the return payload (temp-file path and size, inline attachment under 512 KB), and the override semantics of page_settings. These are behaviors an agent cannot infer from the schema and would otherwise be surprised by.

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?

Four short paragraphs, each doing distinct work: what it does, when to use it vs alternatives, what data means, and the page_settings override plus return/watermark notes. Front-loaded with the core purpose and no filler sentences.

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 tool with three parameters, nested objects, and no output schema, the description covers selection, sibling routing, the single-row constraint, override behavior, and the return value including the free-plan watermark. Nothing an agent needs to call it correctly 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 description coverage is 100%, so the schema already documents data as Jinja variables and page_settings fields, making 3 the baseline. The description adds genuine meaning beyond the schema by stating that `data` supplies exactly one row's worth of values and that omitting page_settings preserves the template's saved setup while passing it overrides only for this render.

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 and resource ('renders one PDF from a template already saved in the user's account') and explicitly contrasts with the sibling render_pdf ('Use render_pdf instead when you are writing the HTML yourself'). An agent can distinguish this from render_pdf, design_template, and create_batch_job without opening any 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 conditions for use ('when the user wants a document in their existing design'), the source of the required id ('Get `template_id` from list_templates'), the alternative tool for a different case (render_pdf), and the escalation path for multi-row output (create_batch_job after create_dataset/upload_dataset). This is explicit when/when-not/alternatives coverage.

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