pdf_metadata

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

With no annotations, the description carries the full burden and does so well: it discloses the dual Info/XMP storage, that they often disagree, the normalized top-level answer, the `sources`/`conflicts` fields, verbatim `info`/`xmp`, and warns against quoting one value as fact. It does not discuss permissions, rate limits, or error behavior on unreadable/invalid PDFs, so it stops short of full coverage.

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-loaded with purpose and alternatives before the deeper behavior notes, and every sentence carries information. It is somewhat long for a one-parameter reader, with the conflict-handling prose edging toward output-schema territory, but nothing is filler.

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 needn't be explained, yet the description still supplies the interpretation rule (prefer XMP, surface conflicts, don't assert a value when has_conflicts is true) that the schema alone would not convey. For a single-param reader with rich output, an agent has everything it needs.

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% and the lone parameter is documented only as 'ref', so the description must compensate — and it does, explaining ref is either a PDF file path or a workspace artifact id. That resolves the main ambiguity (path vs. artifact id) but adds no format examples or constraints.

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?

Opens with a specific verb and resource ('Read a PDF's document properties') and enumerates the fields returned. It explicitly separates itself from pdf_page_count and pdf_check_text, so an agent can route without opening either 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?

Gives a crisp use condition ('who made this, when, and with what') and names two named alternatives for the adjacent asks (page counting, text extractability). Both when-to-use and when-not-to-use are stated, not inferred.

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