preview_pdf_page

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

With no annotations, the description carries the full burden. It does not disclose side effects, rate limits, size constraints, or error behavior for invalid inputs. The description is minimal and leaves the agent uninformed about important behavioral traits.

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 concise (5 lines), front-loaded with the main purpose, followed by a clear parameter list. Every line adds value without redundancy.

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?

The description covers the core functionality and outputs (Base64-encoded PNG). However, it lacks information on error handling (e.g., invalid PDF, page out of range) and does not specify any size or performance limits. Given the tool's simplicity, it is mostly complete.

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?

The description adds meaning to each parameter beyond the schema: pdf_base64 is 'Base64-encoded PDF file', page is 'Page number (1-based, default: 1)', dpi is 'Resolution in DPI (default: 150)'. Since schema description coverage is 0%, this is valuable context.

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 tool's purpose: 'Render a PDF page as a PNG image preview.' It specifies the verb (render), resource (PDF page), and output format (PNG), distinguishing it from sibling tools like extract_text_from_pdf or merge_pdfs.

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 provides no guidance on when to use this tool versus alternatives, nor does it mention prerequisites or limitations. Usage is only implied by the purpose statement.

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