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

Annotations already provide destructiveHint=false and idempotentHint=true, and the description adds useful context about preserving order and the accepted selection syntax. However, the phrase 'out of a PDF' is ambiguous about whether the original file is modified, and the description does not explicitly say the source remains unchanged.

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 concise sentences with no wasted words. The main action is front-loaded, and the second sentence provides a concrete, useful selection example without elaboration.

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?

Given the simple operation and thorough schema, the description is nearly complete for invoking the tool correctly. It clearly states the output is a new PDF and gives a practical selection example, though it could additionally clarify original-file behavior and differentiate from remove_pages.

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 file, pages, and output_filename in detail. The description contributes only the page-selection example, which mostly mirrors the schema's pages parameter description, adding little new semantic value.

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 and resource: 'Pull selected pages out of a PDF into a new PDF.' It also clarifies that page order is preserved, which distinguishes it from reordering tools. The purpose is immediately clear and not a tautology.

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 implies when to use the tool: when a subset of pages needs to be extracted into a new PDF. However, it does not explicitly contrast this with sibling tools like remove_pages or reorder_pdf_pages, nor does it state when not to use it.

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