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

With no annotations, the description carries the burden. It indicates a read-only extraction operation and describes the tool as 'Browser-based', a useful trait. However, it doesn't disclose output format, limitations (e.g., scan quality, language support), or privacy/processing details, so it's adequate but not rich.

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?

The description is a single concise sentence that fronts the core action and includes a parenthetical note. Every word earns its place, with no redundancy or 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?

Given the tool's simplicity (0 params, no output schema), the description covers the essential input (scanned PDF) and output (Japanese text). It lacks details like supported file sizes or whether it works only with Japanese-language PDFs, but it is sufficient for an agent to select this tool over other PDF tools.

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?

The tool has zero parameters, and the schema is an empty object, so description adds no parameter-specific meaning. Per rubric, 0 params baseline is 4, and there is no need for the description to clarify parameters.

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 clearly states 'extract Japanese text from scanned PDF', with a specific verb (extract), resource (scanned PDF), and scope (Japanese text). This distinguishes it from sibling PDF tools like pdf-compress or pdf-split, and the title 'PDFのOCR' reinforces the OCR purpose.

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 description provides no guidance on when to use this tool versus alternatives. It doesn't mention 'use for scanned PDFs' or contrast with pdf-to-word or scan-pdf. No exclusions or alternative suggestions are given.

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