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

No annotations are provided, so the description carries the full burden. It implies a non-destructive read (output is a 'new PDF'), but says nothing about whether the source is modified, permission/auth requirements, size limits, or error behavior for out-of-range pages.

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?

Three compact lines, front-loaded with the purpose and followed by per-parameter notes. No filler, though the terse style leaves no room for usage guidance.

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?

An output schema exists, so return values need not be explained, and both parameters are covered. However, with no annotations and no usage or error guidance, the definition is only minimally complete for a tool that produces a derived file.

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 0%, so the description must compensate, and it does: file_url is documented as a public URL of the PDF, and pages as a 1-based list whose order is preserved. This adds real semantics the bare schema lacks, though duplicate/out-of-range handling is unstated.

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?

States a specific verb and resource: 'Извлекает выбранные страницы в новый PDF' (extracts selected pages into a new PDF). This distinguishes it from delete_pages, reorder_pages and split_pdf, though it does not name those siblings explicitly.

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?

There is no explicit when-to-use or when-not-to-use guidance. With siblings like delete_pages, reorder_pages and split_pdf, the agent gets no criteria for choosing extract_pages over them; usage must be inferred from the verb alone.

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