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

Annotations already cover read-only and non-destructive behavior. The description adds valuable behavioral details: it returns base64 PDF with page count and size, and mentions constraints (200 KB, inline CSS) and 'real Chrome' for rendering fidelity. No contradiction with 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 sentences deliver the purpose, constraints, and output format with no fluff. The core action is front-loaded, and every phrase adds information. The structure is efficient and scannable.

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 conversion tool, the description covers the main input and output format, including size limits and rendering engine. It does not elaborate on optional parameters, but these are self-explanatory from the schema. The absence of an output schema is mitigated by the explicit return description.

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 0%, so the description must compensate for undocumented parameters. However, it only mentions the html input indirectly and provides no explanation of format, landscape, or page_numbers. The schema's self-explanatory names and defaults are the only help, leaving the agent to infer these parameters' effects.

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 clearly states the verb 'Print' (convert) and the resource 'HTML document' to PDF, with specific use cases (invoice, report, receipt) and a size constraint. It distinguishes from sibling url_to_pdf by implying HTML input rather than a URL, making the tool's role 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 clear context for when to use this tool (HTML input, specific document types) and implies the alternative is url_to_pdf for URL input, but it does not explicitly name the sibling or state when not to use it. The use-case hints are helpful but exclusionary guidance is absent.

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