watermark

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It only states the basic action and does not mention whether the original file is modified or a new file is created, nor any side effects like permissions or reversibility. The output behavior is only hinted at by the output_name parameter in the schema, not by the description itself.

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, well-structured sentence that immediately communicates the tool's function without any redundant content. It is concise and front-loaded.

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?

For a simple PDF manipulation tool with 5 parameters and no output schema, the description covers the core functionality ('add text watermark to all pages') and the schema provides parameter details. However, it could be more complete by explicitly stating the output file behavior or that the original is preserved. Overall, adequate.

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 schema covers all 5 parameters with clear descriptions (e.g., opacity 0-1, rotation in degrees, output_name default). The description adds no additional parameter semantics, but given 100% schema coverage, the baseline score of 3 is appropriate.

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 uses a specific verb 'Add' and identifies the resource 'text watermark overlay' applied to 'all pages of a PDF'. This clearly distinguishes it from sibling tools like add_stamps or add_header_footer, making the purpose unambiguous.

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?

Usage is implied by the name and description, but no explicit guidance is given on when to prefer this tool over alternatives such as add_stamps or add_header_footer. There are no exclusions or alternative tool mentions, so the guidance is minimal but not misleading.

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