add_watermark

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

With no annotations, the description carries the full burden and does so richly: auto-backup behavior, backup=False semantics, atomic validated save, and refusal to operate on documents open in Word are all disclosed. This goes far beyond a generic 'add watermark' statement.

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?

Three tightly packed sentences, front-loaded with the core purpose and followed by consequential operational details. Every sentence adds useful information without 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?

The description covers purpose, placement, Word compatibility, backup behavior, save behavior, and an important failure condition. It does not explain how the tool interacts with an existing watermark, but the output schema and self-explanatory parameter names cover most remaining needs.

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. It directly explains the `backup` parameter and partially clarifies `text` and placement. However, `color`, `opacity`, `diagonal`, and `file_path` are left to inference from names/defaults rather than described.

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 states the exact operation: 'Add a text watermark behind the text on every page,' with placement detail and Word compatibility. This clearly distinguishes it from the sibling `remove_watermark` tool by verb and resource.

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 purpose is clear enough that an agent knows when to call it, and the Word Remove Watermark compatibility note implies removal is handled by Word/another tool. However, it does not explicitly name alternative tools or state when not to use it.

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