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

No annotations are provided, so the description carries the full disclosure burden. It does add real behavioral context: UTF-8 encoding, per-page text layout, paragraph/column blocks, and per-word coordinates. It omits permission needs, size limits, and crucially whether scanned PDFs need OCR first — a significant gap for a text-extraction tool with zero annotation 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 the core action, then parameter definitions in a compact structured list. Every line earns its place; the mode sub-bullets are informative rather than padding.

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-value explanation is not required. For a two-param file-producing tool the definition is mostly adequate, but the absence of any OCR/scanned-PDF guidance leaves a real routing gap when sibling ocr_pdf exists.

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 0%, so the description must compensate, and it does: file_url is defined as a public URL of the PDF, and each of the three mode values is explained with its output shape. Minor gap — it does not clarify mode's default placement alongside the schema's default, but coverage of both params is solid.

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: extracts text from a PDF into a .txt file, and pins the encoding (UTF-8). This clearly separates it from pdf_to_word, pdf_to_excel, and pdf_to_pptx, which produce different formats. An agent can identify the tool's job without opening the 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?

The mode enumeration implies when to choose text vs blocks vs words, which is useful implied guidance. However, it never states when this tool is the wrong choice — notably it does not point to ocr_pdf for scanned/image PDFs, which is the single most important routing decision here. Usage is implied, not explicit.

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