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

The annotations only provide generic hints, so the description adds meaningful behavioral context: the input is never modified, repeated page references are copied twice, and the free tier is capped at 30 pages. These details go well beyond the annotation flags and help an agent predict side effects and limits.

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 sentences with no filler. The core instruction is front-loaded, and the example plus caveats are high-signal and directly useful for invocation.

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 covers the operation, page-selection rules, input safety, and a usage limit, while the schema documents all parameters and the download-link behavior. Naming sibling tools for routing would improve it further, but the current guidance is sufficient for correct usage.

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%, so the baseline is 3. The description adds value by explicitly clarifying page ordering and duplicate-copy behavior for the 'pages' parameter, which complements the schema's examples rather than merely repeating them.

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 (pull/extract) and resource (selected pages into one new PDF), making the tool's function unmistakable. It is clearly distinct from sibling tools like pdf_merge, pdf_split, and pdf_reorder because it focuses on selecting existing pages into a single output PDF.

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 opening phrase 'Call this tool to pull selected pages into one new PDF' gives an unambiguous use case. It does not explicitly name sibling alternatives or exclusion conditions, but the intended scenario is clear enough for an agent to select it correctly.

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