resize_image

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

With no annotations, the description carries the burden and does add useful behavioral detail: the Lanczos algorithm and the aspect-ratio preservation behavior. However, it does not disclose what happens when keep_aspect is false, whether files are overwritten or written to a new output, or any permissions/limitations.

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?

Two focused sentences, front-loaded with the core action and followed by the edge-case behavior. No filler or repetition, and every clause adds information.

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 core resizing behavior is complete enough for a basic call, and the output schema covers return values. Clear gaps remain around side effects (e.g., whether the input file is modified), supported formats, and the false branch of keep_aspect, which an agent may need to predict behavior.

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%, but the description compensates partially by explaining how width/height and keep_aspect interact ('fits within width x height without distorting'). It does not explain image_path semantics or the behavior when keep_aspect is false, leaving some parameter meaning to inference.

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 uses a specific verb-resource pair ('Resize an image') and adds a concrete behavior ('fits within width x height without distorting', 'Lanczos resampling'). It does not explicitly differentiate itself from sibling resize-related tools like upscale_image or convert_format, so it falls short of full sibling-level distinction.

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?

No guidance is given about when to choose resize_image over sibling tools such as upscale_image, remove_background, or convert_format. The usage context is only implied by the name and description, with no exclusions, preconditions, or alternative routing.

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