pdf_add_watermark

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

With no annotations, the description carries full burden but lacks behavioral details. It states the tool modifies PDFs (implied mutation) but doesn't disclose if it's destructive to the original file, requires specific permissions, has rate limits, or what happens on failure. This is a significant gap for a tool that alters files.

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, efficient sentence that front-loads the core purpose ('Add a text watermark to all or specific pages of a PDF'). It wastes no words and is appropriately sized for the tool's complexity.

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 mutation tool with no annotations and no output schema, the description is incomplete. It doesn't explain what the tool returns (e.g., success status, error messages), behavioral traits like file handling, or usage context, leaving gaps that could hinder an AI agent's correct invocation.

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 100%, so parameters are well-documented in the schema. The description adds minimal value beyond implying 'pages' parameter usage for targeting, but doesn't provide additional context like format examples or constraints beyond what the schema already covers.

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 action ('Add a text watermark') and resource ('to a PDF'), specifying it can target 'all or specific pages'. It distinguishes from sibling tools like pdf_rotate or pdf_merge by focusing on watermarking, though it doesn't explicitly contrast with them.

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?

No guidance is provided on when to use this tool versus alternatives. While the description implies it's for adding watermarks, it doesn't mention prerequisites (e.g., file permissions), when not to use it, or how it compares to similar tools like pdf_set_metadata for document marking.

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