invert_colors

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

The description clearly states the core action (invert colors of all pages), but with no annotations, it fully bears the burden of disclosing behavior. It does not specify whether the original file is overwritten or a new file is created, nor does it mention any side effects or prerequisites. The schema's default output_name hints at output behavior, but the description itself lacks this detail.

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, concise sentence that communicates both the function and a relevant use case without any redundant or extraneous information. It is perfectly front-loaded and efficient.

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 the tool's simplicity and comprehensive schema, the description is adequate but not complete. It fails to explicitly mention output behavior (new file vs. overwrite) and does not address potential side effects or limitations. With no annotations or output schema, these gaps are notable for an agent deciding whether and how to invoke the tool.

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 already provides descriptions for both parameters (file and output_name) with 100% coverage. The description adds no additional parameter-specific meaning, so the baseline of 3 applies for high schema coverage.

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 function with a specific verb ('Invert') and resource ('colors of all pages'), effectively distinguishing it from related tools like pdf_to_greyscale. The parenthetical 'useful for dark mode printing' adds contextual purpose without ambiguity.

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 provides a clear use case ('useful for dark mode printing'), giving agents context for when to use it. However, it does not explicitly mention alternatives or exclusion criteria, so it misses the top score for complete usage guidance.

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