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

Annotations already indicate readOnlyHint=false and destructiveHint=false, establishing that this is a mutating but non-destructive operation. The description does not add behavioral details such as what output is returned, whether the original file is preserved, or what happens if no adjustment parameters are supplied, but it does not contradict the annotations.

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 front-loaded sentence with no wasted prose. The 'Color Adjuster —' prefix repeats the annotation title, and the '[category: photo]' tag is mild noise, but overall the description is appropriately compact.

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 schema handles parameter documentation well, and the operation is simple enough that the description is minimally viable. However, there is no output schema and the description does not explicitly state that the tool returns the adjusted image or how the result is delivered, leaving a modest gap for an agent invoking it correctly.

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%, and the schema already provides rich semantics for contrast, brightness, and saturation, including ranges, defaults, and special warnings. The tool description merely names the same properties without adding new meaning, so 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 states a specific action and object: 'Adjust brightness, contrast, and saturation of an image.' This clearly distinguishes the tool from siblings like photo_editor, photo_crop, and photo_compress, which handle different or broader image operations. The purpose is immediately understandable.

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 gives no guidance on when to choose this tool over alternatives such as photo_editor or photo_face_blur. It does not mention exclusions, prerequisites, or use-case boundaries, so an agent cannot tell when this tool is the intended choice versus a sibling.

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