pdf_info

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly signals read-only behavior ('读取') and, more importantly, specifies the coordinate system (top-left origin, y-down, pt units), which is behavioral information not available in the schema.

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 output scope and usage context are front-loaded, and the coordinate convention is a purposeful addition rather than redundancy.

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?

There is no output schema, but the description enumerates the return content and gives the coordinate convention, which is essential for interpreting results. It is sufficient for a read-only inspection tool, though exact output field names/types are left unspecified.

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 fully documents path, maxPages, and password. The description adds no parameter-level detail beyond that, matching the baseline for high schema coverage.

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 ('读取') and resource ('PDF') and enumerates the exact outputs: page count, per-page dimensions/rotation, and metadata. This clearly differentiates it from sibling tools pdf_extract and pdf_render by framing it as document-level inspection.

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?

It explicitly gives a concrete use case: understand structure and decide which pages to process before extraction. It doesn't explicitly say when not to use it or name alternatives, but the stated pre-extraction context is strong enough to guide selection.

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