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

Annotations indicate readOnlyHint=false and destructiveHint=false, meaning it modifies the image but is not destructive. The description adds no additional behavioral context, such as whether the original file is overwritten or a new file is returned, or any auth or rate-limit constraints. Since the tool is a mutation operation and the description does not disclose the output behavior, it falls short of the transparency expected even with annotations present.

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, direct sentence that front-loads the core purpose. It contains no filler or redundant information, and the category tag is minimal and useful. Every word earns its place.

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?

While the schema covers parameters, there is no output schema, and the description does not state what the tool returns (e.g., a modified image file in the same format). Given the number of sibling photo tools, the agent needs to know the return behavior to use it correctly. The description is also silent on any side effects or limitations beyond what the schema mentions. This is a significant gap for a mutation 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 provides detailed descriptions for all four parameters (file, contrast, brightness, saturation) with units, ranges, and defaults. With 100% schema coverage, the description does not need to add parameter information, and it does not. The baseline of 3 is appropriate since the schema carries the full semantic load.

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 (adjust) and the resource (an image) along with the specific properties (brightness, contrast, saturation). This is precise and distinguishes it from other photo tools like photo_crop or photo_editor, which handle different operations. It is not a tautology and gives the agent a specific verb+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 description provides clear context about what the tool does (adjusting color properties), which implies when to use it. However, it does not explicitly mention alternatives or conditions where this tool should be avoided, such as 'use photo_editor for more advanced edits' or 'use photo_resize for dimension changes'. The context is clear but lacks explicit exclusions or sibling differentiation.

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