watermark

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the write/overwrite safety profile is partly covered. The description adds no behavior beyond that: it does not say whether the source PDF is modified in place, that a separate output file is required, or how the overwrite flag behaves. "Across the pages" mildly contradicts the existence of a pages parameter for subsetting.

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?

A single tight sentence with the action front-loaded and no filler. It is efficient, though its brevity is partly under-specification rather than true conciseness given the tool's 8 parameters.

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?

With 8 parameters at 0% schema coverage, no parameter explanations in the description, and a write operation that produces an output file, the description is far too thin. The presence of an output schema excuses return-value details, but required inputs and mutation semantics remain undocumented.

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% across 8 parameters, so the schema documents nothing. The description only echoes the text parameter and vaguely implies page scope; opacity, rotation, font_size, output, overwrite, and the pages selector are all unexplained.

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 names a specific verb ("Stamp") and resource ("text watermark") and gives concrete examples (CONFIDENTIAL, COPY), so the action is unambiguous. It does not, however, differentiate itself from nearby siblings like redact or protect, which also alter page content.

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?

There is no guidance on when to choose watermark over redact/protect, no prerequisites, and no mention of when it is inappropriate. The agent must infer usage entirely from the one-line purpose statement.

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