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

Annotations already declare idempotentHint=true, readOnlyHint=false, and destructiveHint=falseikuha. The description adds that a new PDF is produced (rather than modifying the source) and that page numbers are 1-indexed, which are meaningful behavioral details beyond what the annotations convey.

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?

A single sentence that conveys the operation, the resource, and the key indexing constraint. It is front-loaded with the primary action 'Extract specific pages from a PDF' and wastes no words.

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 only two parameters, full schema coverage, annotations, and an output schema, the description covers the essential behavioral context: subset selection, new PDF output, and 1-indexing. It omits only explicit usage distinctions from sibling tools, which is a minor 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 already provides descriptions for both parameters (file and page_numbers) at 100% coverage. The tool description adds the crucial '1-indexed' detail for page_numbers and clarifies the operation's intent, which complements the schema instead of repeating it.

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 'Extract', the resource 'specific pages from a PDF', and the output 'a new PDF'. It differentiates itself from siblings like split_pdf or merge_pdfs by emphasizing 'specific pages' and the resulting single new PDF, which an agent can use to select the right tool.

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 is needed from an existing PDF) but does not explicitly contrast it with split_pdf, merge_pdfs, or other alternatives. No when-not-to-use guidance is provided, leaving some inference to the agent.

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