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

With no annotations, the description fully discloses key behaviors: opens a widget for drawing/typing/uploading, optionally pre-renders a signature, and emphasizes that all processing is local and the file is never uploaded. This is comprehensive and honest.

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 informative but includes a lengthy Polish translation that may be redundant for an English-speaking agent. The key information is front-loaded in the first sentence, but the bilingual structure adds verbosity.

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 no output schema, the description adequately covers what the tool does (opens a widget for user interaction and download) and its local processing nature. It is complete enough for an agent to understand the tool's behavior and expectations.

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 input schema has 100% description coverage, but the tool description adds value by explaining that signature_name renders a 'handwritten-style signature the user can place and adjust,' going beyond the schema's generic description. The file parameter is not further elaborated.

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 the tool's purpose as 'sign a PDF' and explains it opens an interactive widget for user input. It distinguishes from siblings like fill_pdf_form, merge_pdfs, and split_pdf by focusing specifically on PDF signing.

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 explicitly instructs to 'ALWAYS use this for PDF signing requests' and warns against signing or modifying the PDF directly, providing clear usage context. However, it does not explicitly contrast with siblings or mention when not to use it beyond the directive.

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