pdf_highlight

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

No annotations are provided, so the description must disclose behavioral traits. It mentions 'translucent' and the analogy to a highlighter pen, but does not explain whether the tool modifies the original file or creates a new one, nor any other side effects or permissions needed.

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 very concise (two sentences) and front-loads the core functionality. It is efficient, though could include more structured detail about output.

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 does not mention the output (e.g., a new PDF with highlights) despite no output schema. It also lacks context about required parameters like outputPath and what the tool produces. For a modification tool, this is a significant gap.

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 input schema covers all parameters with descriptions, so the description adds little beyond the analogy to a highlighter pen. The schema already explains opacity, color, coordinates, etc., making additional description redundant.

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 ('add') and resource ('translucent highlight boxes over regions on PDF pages') and distinguishes from sibling tools like pdf_add_text or pdf_draw by explicitly comparing to a highlighter pen. It clearly states the tool's function.

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 says 'Great for marking important sections,' which implies when to use. However, it does not explicitly mention when not to use or provide alternatives, though the sibling list implies the tool is for highlighting only.

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