Extract PDF pages

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

Annotations already flag this as non-read-only and destructive, and the description adds useful behavioral detail: the original PDF is left untouched, pages are 1-based, and order is preserved. The overwrite behavior is not repeated in the description, but the overwrite parameter schema and destructiveHint annotation already cover that risk.

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 with a front-loaded purpose, a compact example of page syntax, and no filler. Every clause contributes: local file, original untouched, 1-based indexing, list/range support, and order preservation.

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 4-parameter tool with an output schema and full schema descriptions, the description covers the essential operation, page-selection semantics, and non-destruction of the source. It does not cover edge cases such as invalid page numbers, but the schema and annotations carry the rest of the contract.

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 coverage is 100% for all four parameters, so the baseline is 3. The description adds value beyond the schema by clarifying that page order is preserved, so '3,1' produces a two-page file in that order—a non-obvious behavioral detail for the pages parameter.

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 opens with a specific verb and resource: 'Write a selection of pages from a local PDF into a new file'. It clearly distinguishes the tool from siblings like merge_pdfs (combining PDFs) and pdf_info (inspecting PDFs) by describing the exact extraction operation.

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: use this tool when you need selected pages from a local PDF written to an output file. It does not explicitly name when-not conditions or alternatives, so it stops short of the top tier, but the intended use is unmistakable.

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