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

Goes well past the annotations by disclosing that the call SPENDS CREDITS, the billing model (per request or per page, extra components can add cost), the pricing reference and the free-credit starting balance. It also states the input exclusivity constraint and the POST endpoint. It doesn't explain the unusual readOnlyHint=false for what looks like a read, or timeout/error behavior, so not a 5.

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?

Front-loads the cost warning and the returned fields, which are the two most decision-relevant facts, and is mostly sentence-efficient. The billing sentence is dense and the 'EUR 25 of free credit' detail is marginal, keeping it just under full marks.

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?

With no output schema, the description usefully names what is returned (page count, sizes, content type, metadata, permissions), and it covers the mutually-exclusive input modes for a 6-parameter, zero-required tool. Costs and inputs are covered; error/timeout handling on the 30-second download is only covered by the schema, not the description.

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, but the description adds a genuine constraint absent from the schema: the document must be supplied as exactly one of url/data_base64/file_id, plus a size hint ('small files' for base64). That one-of exclusivity is real semantic value the schema does not encode (no required fields, no oneOf).

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 ('info' on a PDF/TIFF) and enumerates exactly what it returns: page count, page sizes, content type, metadata and permissions. It also positions itself against the capture siblings by naming the pre-capture page-count check, so an agent can tell it apart from dochorizon_capture_* without opening a schema.

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?

'Useful to check the page count before capturing' gives a concrete when-to-use scenario tied to the sibling capture tools. It does not state explicit exclusions or when another toolkit tool (e.g. render/split) is preferable, so it falls short of full routing guidance.

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